Bar to PSI Converter: EU Tire Pressure, Hydraulic Systems, Scuba Tanks, Barometric Pressure, and Pressure Cookers in US Measurements
Convert bar to psi instantly. 1 bar = 14.504 psi. 2.2 bar = 31.908 psi (EU car tire). 2.5 bar = 36.259 psi (EU SUV). 200 bar = 2,900.755 psi (EU scuba). 1 mbar = 0.01450 psi (weather). 1 bar = 100 kPa exactly. BIPM and NIST SP 811 derivation. Free PDF report and batch converter included.
Bar to PSI Calculator
Enter a pressure to convert
EU tire spec: 2.2 bar front (31.9 psi), 2.5 bar SUV rear (36.3 psi). EU scuba: 200 bar = 2,900.8 psi. 1 mbar = 0.01450 psi. Weather: ~1,013 mbar = 14.696 psi at sea level.
EU-to-US Pressure Range Chart (0-12 bar, hover for psi)
When International Meets American: Why You Need Bar to PSI in the United States Today
The United States remains one of the few countries where everyday pressure measurement stays firmly in psi. Walk into any Walmart, O’Reilly Auto Parts, or Home Depot and every tire gauge, pressure washer, and air compressor carries its specs in pounds per square inch. Yet the world increasingly ships into the US in bar. A European-manufactured BMW or Volkswagen has a door-jamb placard stamped in bar. A UK-trained diver renting equipment at a US dive shop reads psi on the tank gauge and gets confused. A commercial kitchen installing a German-spec Rational combi oven gets a service manual with steam pressures in bar. A hydraulic press imported from Italy comes with maintenance specs in bar. In all these everyday situations, a fast and exact bar-to-psi converter is not just convenient, it is operationally necessary to avoid real mistakes: underinflating tires by 10-15%, overfilling dive tanks, or misreading an equipment fault condition.
The bar unit was formally defined by the International Bureau of Weights and Measures (BIPM) as exactly 100,000 pascals. Since 1 Pascal = 1 N/m squared, and 1 bar = 100,000 N/m squared, bar is a rounded-off, convenient near-atmosphere metric unit (standard atmospheric pressure is 1.01325 bar, not exactly 1 bar). The psi, pounds per square inch, derives from the US customary pound-force divided by area in square inches. From NIST SP 811: 1 lbf = 0.45359237 kg times 9.80665 m/s squared = 4.4482216152605 N (exact chain), and 1 in squared = 0.00064516 m squared exactly. So 1 psi = 4.4482216152605 / 0.00064516 = 6,894.75729316836 Pa exactly. Dividing: 1 bar = 100,000 / 6,894.75729316836 = 14.503773773020924… psi, a non-terminating decimal requiring precise arithmetic to avoid rounding errors that compound across fleets or fill logs.
How This Bar to PSI Converter Works
Enter any pressure in bar or psi. The calculator converts to all five units simultaneously: psi (primary when converting from bar), bar (primary when converting from psi), kPa (note: 1 bar = 100 kPa exactly, making this the easiest conversion of all), Pa (SI base unit used in engineering calculations), and atm (standard atmospheres, relevant for diving and atmospheric science where 1 atm = 1.01325 bar = 14.696 psi). The context panel identifies what your bar reading means in everyday American terms: whether it is a dangerously flat tire, an EU vehicle’s recommended cold inflation equivalent in psi, shop air pressure, or a scuba fill pressure. The chart shows the 0-12 bar range most commonly encountered, with the green zone marking the EU tire pressure sweet spot (1.8-2.7 bar = 26.1-39.2 psi), red marking dangerously low pressure below 1.8 bar (26.1 psi), and orange covering the industrial range. Batch mode converts up to 20 pressures at once, useful for fleets of imported vehicles or dive fill logs.
Bar-to-PSI Reference for EU Vehicle Owners at US Gas Stations
| EU Tire Placard (bar) | US Equivalent (psi) | kPa | US Vehicle Type Match |
|---|---|---|---|
| 1.9 bar | 27.6 psi | 190 kPa | Compact car front (economy range) |
| 2.0 bar | 29.0 psi | 200 kPa | EU compact front; US compact lower end |
| 2.1 bar | 30.5 psi | 210 kPa | EU mid-size front / US compact standard |
| 2.2 bar | 31.9 psi | 220 kPa | Most common EU front tire spec |
| 2.3 bar | 33.4 psi | 230 kPa | EU mid-size rear / US mid-size standard |
| 2.4 bar | 34.8 psi | 240 kPa | EU mid-size rear (performance tires) |
| 2.5 bar | 36.3 psi | 250 kPa | EU SUV rear / US light truck common |
| 2.6 bar | 37.7 psi | 260 kPa | EU SUV / performance model rear |
| 2.7 bar | 39.2 psi | 270 kPa | EU sport model high-load rear |
| 2.9 bar | 42.1 psi | 290 kPa | EU full-size van / heavy load |
| 3.0 bar | 43.5 psi | 300 kPa | EU commercial van or full tire load |
Three Real US Situations That Require Bar to PSI Conversion
German Immigrant Filling Tires at a US Gas Station After Importing a VW Golf from Europe
A German family moves to Chicago, Illinois and ships their Volkswagen Golf R from Frankfurt. The door-jamb sticker on the car reads: Front 2.3 bar (33.4 psi), Rear 2.5 bar (36.3 psi), with maximum load Rear 2.8 bar (40.6 psi). At their first US gas station stop, the air machine shows only psi. Converting the full tire schedule: 2.3 bar times 14.5038 psi/bar = 33.359 psi, rounded to 33 psi front. 2.5 bar times 14.5038 = 36.259 psi, rounded to 36 psi rear. Their Golf also has VW’s Tyre Pressure Monitoring System (TPMS), calibrated in bar by the manufacturer, but the US-sold version recalibrates to alert at 25% below the psi equivalent as required by NHTSA FMVSS 138. The family also notes that the European service manual specifies cold inflation, meaning tires that have not been driven for at least three hours, exactly matching NHTSA’s definition, so the conversion applies directly without any temperature adjustment.
UK-Trained Commercial Diver Renting US Equipment in Key West, Florida
A British commercial diver arrives at a Key West dive operation for a coral restoration project. In the UK, all dive shop fill stations use bar gauges, and his diving experience is entirely in bar: he is trained to start dives at 200 bar, turn at 130 bar, and surface above 50 bar. The US dive shop fills aluminum 80 cylinders to 3,000 psi (206.84 bar) and uses submersible pressure gauges (SPGs) that read in psi. He needs to translate his entire mental framework: 200 bar times 14.5038 = 2,900.76 psi (approximately his accustomed full fill). 130 bar times 14.5038 = 1,885.5 psi (his turn-around point). 50 bar times 14.5038 = 725.2 psi (his minimum surface pressure). The US dive instructor explains the shop uses the “rule of thirds” in psi: start at 3,000 psi, turn at 2,000 psi, surface with 1,000 psi, which corresponds closely to the British 200-130-65 bar convention. The diver also notes that the US AL80 cylinder at 3,000 psi holds approximately 77.4 cubic feet of air, while a European 12-liter steel cylinder at 200 bar holds 200 times 12 liters = 2,400 liters = approximately 84.8 cubic feet, so the US cylinder is slightly smaller in total air volume.
Restaurant Owner Installing a European Commercial Steam Oven in a Houston, Texas Kitchen
A Houston restaurant owner imports a German-manufactured Rational SelfCooking Center combi oven, which requires a water supply and steam injection system. The European service manual specifies: inlet water pressure 1.5-6.0 bar (21.8-87.0 psi), optimal 2-4 bar (29.0-58.0 psi), maximum 8 bar (116.0 psi). The Houston city water supply delivers approximately 70 psi (4.83 bar) at the building meter, well within the 1.5-6.0 bar (21.8-87.0 psi) acceptable range for the oven without a pressure-reducing valve. However, at kitchen service peaks when multiple fixtures run simultaneously, the incoming pressure drops to about 45 psi (3.10 bar), still within the acceptable range. The owner also needs to verify that the existing 0.5-inch supply line provides adequate flow rate in gpm (gallons per minute) rather than the European l/min specification. The biomedical equipment technician cross-references the 8 bar (116 psi) maximum with the US PRV (pressure-reducing valve) set to 60 psi (4.14 bar) protecting all kitchen appliances, confirming the PRV is set well below the oven’s 8 bar (116 psi) absolute maximum, providing appropriate safety margin.
Four Expert Tips on Bar-to-PSI for Drivers, Divers, and Technicians in the US
EU Tire Placards in the US: Finding the Bar Sticker and Filling at an American Gas Station
Every passenger vehicle sold in the US must have a tire placard with recommended cold inflation pressures per FMVSS 110. Imported European vehicles have the required placard but may express pressures in bar (the EU standard per UN Regulation 64) rather than psi, depending on the importing dealer’s localization process. If your vehicle shows a bar value, use this converter: 2.2 bar = 31.9 psi (round to 32 psi); 2.4 bar = 34.8 psi (round to 35 psi); 2.5 bar = 36.3 psi (round to 36 psi). US gas station air machines almost always show psi only. The US law requires TPMS (Tire Pressure Monitoring Systems) to alert at 25% below the recommended cold psi: a 2.2 bar (31.9 psi) recommended tire gets a TPMS alert at approximately 23.9 psi (1.648 bar). One practical note: always check cold, especially on imported vehicles with low-rolling-resistance tires that maintain pressure longer but respond more dramatically to temperature changes in continental US climates between summer and winter.
Gauge Pressure (barg) vs Absolute Pressure (bara): Why the Same Number Can Mean Two Different Things
Bar appears in two forms in European and international documentation: bar gauge (barg) and bar absolute (bara). Gauge pressure is measured relative to ambient atmospheric pressure, meaning 0 barg = atmospheric (not a vacuum). Absolute pressure is measured from true zero (perfect vacuum). Standard atmosphere: 1.01325 bar absolute = 14.696 psia. Tire pressure is always gauge: a car tire at 2.2 barg has an absolute pressure of 2.2 + 1.01325 = 3.21325 bara (46.6 psia). Scuba tanks at 200 barg = 200 + 1.01325 = 201.01 bara (2,915.5 psia). In the US: psi gauge (psig) vs psi absolute (psia) follows the same distinction. When a European equipment manual says “operating pressure 4 bar,” it almost always means 4 barg unless explicitly stated otherwise. Converting 4 barg to psig: 4 times 14.5038 = 58.015 psig. To get psia: add 14.696, giving 72.7 psia. Most US pressure gauges read psig automatically (they zero at atmospheric). Confusion between gauge and absolute is a common and potentially dangerous source of error when converting European pressure specs for US equipment.
The Pressure Cooker Bar-to-PSI Calculation and What It Means for Safe Cooking
All traditional stovetop pressure cookers are designed to operate at approximately 15 psi (1.034 bar) above atmospheric pressure, giving a total absolute pressure of about 29.7 psia (2.047 bara). At 15 psig (1.034 barg), water’s boiling point rises from 212 degrees Fahrenheit (100 Celsius) to approximately 250 degrees Fahrenheit (121 Celsius), which is also the sterilization temperature used in autoclaves. Modern electric pressure cookers (Instant Pot, Breville Fast Slow Pro, Ninja Foodi) typically operate at High Pressure of 10.2-11.6 psi (0.703-0.800 bar) above atmospheric. European pressure cooker brands (WMF, Fissler, Lagostina) specify operating pressure in bar: the WMF Perfect Pro operates at 0.7 bar gauge (10.2 psi gauge), while the Fissler Vitaquick is 0.9 bar gauge (13.1 psi gauge). Traditional US Presto and Mirro cookers operate at 15 psi (1.034 bar) gauge, the USDA-recommended minimum pressure for safe low-acid food canning. Always consult current USDA National Center for Home Food Preservation guidelines for canning pressure and time, as these are calibrated to the 15 psi (1.034 bar) standard.
Technical Atmosphere (at) vs Bar: Reading Old German and Japanese Industrial Manuals
If you are working with older European or Japanese industrial machinery documentation, you may encounter the technical atmosphere unit (at), also written as kgf/cm squared (kilogram-force per square centimeter). This unit was common in German, Italian, and Japanese engineering before widespread SI adoption, and it still appears in manuals for machinery built before the 1990s. Conversion: 1 at = 1 kgf/cm squared = 98,066.5 Pa = 0.980665 bar = 14.223 psi. Note that 1 at is slightly less than 1 bar (which is 100,000 Pa), and both are slightly less than 1 standard atmosphere (101,325 Pa). So when an old German hydraulic press manual says “working pressure 250 at,” that equals 250 times 0.980665 bar = 245.2 bar = 3,556 psi. If that same spec were in bar (250 bar), it would equal 3,626 psi. The difference between at and bar is about 2%, which matters at high industrial pressures but is negligible for tire inflation. Modern machinery has largely switched to bar, MPa (megapascals), or kPa in European documentation and psi or bar in US documentation.
Barometric Pressure in US Weather and Aviation: Millibars, Hectopascals, InHg, and PSI
How NOAA and the National Weather Service Express Atmospheric Pressure
In US weather reporting, the National Weather Service (NWS) and NOAA express surface atmospheric pressure in two units simultaneously: millibars (mbar, equivalent to hectopascals, hPa) for scientific and international reporting, and inches of mercury (inHg) for US consumer weather apps, TV forecasts, and aviation altimetry. The bar-to-psi relationship becomes essential for understanding just how close these units are to everyday pressure. 1 millibar = 0.001 bar = 0.01450 psi. Standard atmospheric pressure at sea level per the International Standard Atmosphere (ISA): 1013.25 mbar = 1.01325 bar = 14.696 psi = 29.921 inHg. A high-pressure system (fair weather): 1025-1040 mbar = 1.025-1.040 bar = 14.869-15.080 psi = 30.27-30.71 inHg. A low-pressure storm system: 980-1000 mbar = 0.980-1.000 bar = 14.214-14.504 psi = 28.94-29.53 inHg. Hurricane Katrina at peak intensity recorded 902 mbar = 0.902 bar = 13.083 psi = 26.64 inHg. The lowest reliably recorded sea-level pressure ever: 870 mbar = 0.870 bar = 12.619 psi in Super Typhoon Tip (1979). Note that these pressures are absolute (psia), not gauge, since weather measurements reference perfect vacuum not local atmosphere. Converting the everyday 1-inch drop on a home barometer: 1 inHg = 33.86 mbar = 0.03386 bar = 0.491 psi.
Aviation Altimetry: QNH, QFE, and the Altimeter Setting in InHg and Millibars
FAA regulations (14 CFR Part 91) require US pilots to set their altimeters using Kollsman windows calibrated in inHg, with a typical range of 27.90-31.00 inHg. International pilots flying into the US may be accustomed to setting QNH in millibars (equivalent to hPa). The conversion: 1 inHg = 33.8639 mbar = 0.0338639 bar = 0.491154 psi. A typical altimeter setting of 29.92 inHg (the ISA standard) = 1013.25 mbar = 1.01325 bar = 14.696 psi. International flights arriving at US airports must switch from mbar altimeter settings to inHg below the transition altitude (18,000 feet MSL in the US, which defines the FL180 lower boundary of Class A airspace). ATIS broadcasts (Automatic Terminal Information Service) in the US report altimeter settings in inHg to two decimal places (e.g., “Altimeter 29.94”). A conversion that pilots must have memorized: 1 mbar change in barometric pressure equals approximately 27 feet of altitude difference at standard conditions, or equivalently, 0.0338639 bar = 0.491 psi corresponds to approximately 900 feet altitude change.
EU Industrial Equipment in US Facilities: Converting Hydraulic and Pneumatic Specs
ISO 4414 Pneumatic Systems vs ANSI/ASME B19 Standards
US and European pneumatic systems for industrial machinery follow parallel but differently-expressed standards. ISO 4414 (Pneumatic fluid power, general rules and safety requirements for systems and their components) expresses all design and working pressures in bar or MPa (megapascals, where 1 MPa = 10 bar). ANSI/ASME B19 Series standards for air compressors and pneumatic systems use psi. Common EU industrial pneumatic working pressures and their US equivalents: 6 bar (87 psi) entry-level tooling and automotive assembly; 8 bar (116 psi) standard EU factory air supply; 10 bar (145 psi) higher-demand production equipment; 12 bar (174 psi) specialty forming and clamping cylinders; 16 bar (232 psi) high-force pneumatic actuators. US facilities importing EU machinery must verify that their existing compressed air supply at 90-125 psi (6.21-8.62 bar) is adequate for the EU equipment’s minimum working pressure. Most EU production equipment requiring 6-8 bar (87-116 psi) operates comfortably on US 90-100 psi (6.21-6.89 bar) plant air, but machinery requiring 10 bar (145 psi) may need a booster compressor or dedicated high-pressure supply line if the existing infrastructure only provides 100-125 psi (6.89-8.62 bar).
Hydraulic Equipment from European Manufacturers: Bar to PSI in Cylinder and Valve Specs
European hydraulic systems for construction equipment (Liebherr, Putzmeister, Schwing) and machine tools (DMG Mori EU models, Trumpf) specify hydraulic pressures in bar, while US manuals for the same or equivalent equipment (Caterpillar, Manitowoc, Haas) use psi. Key hydraulic ranges in bar and psi: mobile construction equipment working pressure 200-350 bar (2,901-5,076 psi); machine tool clamping circuits 60-120 bar (870-1,740 psi); pilot pressure circuits 15-35 bar (218-508 psi); case drain return pressure maximum 3-7 bar (43.5-101.5 psi). Relief valve settings: a 350 bar (5,076 psi) system pressure relief on an EU excavator corresponds to adjusting a US-spec valve to 5,000-5,100 psi. EU hydraulic hose and fitting pressure ratings (per DIN and EN standards) are in bar, while US ratings (SAE J517) are in psi. A DIN-rated hose marked “Maximum Working Pressure 400 bar” = 5,801 psi. The burst pressure safety factor in both systems is typically 4:1, so this hose bursts at approximately 1,600 bar = 23,200 psi or higher.
Beer, Wine, and Beverage Carbonation: CO2 Pressure in Bar vs PSI
Anyone who has imported a European home brewing system, professional draft beer equipment, or a commercial carbonation rig to the United States will encounter pressure in bar. CO2 regulators manufactured in Europe (Vinimat, Taprite EU, Ecobar) display output pressure in bar, while US CO2 regulators (Micro Matic, Taprite US) display in psi. For draft beer dispensing, the required CO2 pressure depends on the carbonation level of the beer and the keg temperature. Typical US commercial draft settings: lager and pilsner at 38F (3.3C) requires 10-12 psi (0.69-0.83 bar). Ales at 38F: 8-10 psi (0.55-0.69 bar). Nitrogen-served stouts (Guinness-style): 25-35 psi N2/CO2 blend (1.72-2.41 bar). European Weizen (wheat beer): higher carbonation, 12-14 psi (0.83-0.97 bar). For sparkling water carbonation at home with a SodaStream-style EU carbonator: 60 psi (4.14 bar) burst pressure for bottles, system pressure capped at about 40 psi (2.76 bar). A homebrewer switching from a European keezer setup to a US CO2 regulator needs to convert: the EU regulator’s recommended 0.7 bar (10.2 psi) output for a cold-stored Belgian golden ale becomes 10 psi on the US gauge, and the 0.9 bar (13.1 psi) for a German Helles becomes 13 psi. Wine bottle carbonation for natural pet-nat: 2-3 bar (29.0-43.5 psi) at room temperature is the typical range for slightly sparkling wines, with traditional Champagne bottles pressurized at 5-6 bar (72.5-87.0 psi) at 55F (13C) cellar temperature.
Bar to PSI in International Shipping and Compressed Gas Cylinders
Industrial and medical gas cylinders exported from Europe to the US carry pressure markings in both bar and psi on their shoulder stampings and test certificates, but the primary rating in EU manufacturing and transport is bar per ADR (European Agreement Concerning the International Carriage of Dangerous Goods by Road). A standard EN 1964 medical oxygen cylinder test pressure is 250 bar (3,625.9 psi), with a working pressure of 200 bar (2,900.8 psi). US DOT (Department of Transportation) equivalent cylinders under CFR 49 show the service pressure in psi: DOT-3AA 2015 oxygen cylinder has a 2,015 psi (138.9 bar) service pressure. When a US importer receives a cylinder manifested at “200 bar” from a European supplier, the DOT import regulations require verifying the US equivalent psi marking or obtaining a requalification. Converting: 200 bar = 2,900.8 psi; this falls within the DOT-3AA 3000 service pressure rating (3,000 psi = 206.8 bar), so a US 3,000 psi cylinder can safely hold gas at the EU 200 bar fill pressure with appropriate safety factor. The practical upshot: EU-filled cylinders at 200 bar are safe in US 3,000 psi-rated cylinders, and US 3,000 psi fills are above EU 200 bar cylinders’ rated working pressure unless the EU cylinder is HP-rated at 232 bar (3,364.9 psi) or 300 bar (4,351.1 psi).
Quick Reference: Common Bar to PSI Conversions
| Bar | PSI | kPa | atm | Context |
|---|---|---|---|---|
| 0.001 bar (1 mbar) | 0.01450 psi | 0.1 kPa | 0.000987 atm | Weather pressure unit (1013 mbar = 1 atm) |
| 1 bar | 14.504 psi | 100 kPa | 0.98692 atm | BIPM definition: 100,000 Pa exactly |
| 1.01325 bar | 14.696 psi | 101.3 kPa | 1.000 atm | Standard atmosphere (ISA sea level) |
| 2.2 bar | 31.908 psi | 220 kPa | 2.171 atm | Most common EU front tire spec |
| 2.5 bar | 36.259 psi | 250 kPa | 2.467 atm | EU SUV and crossover rear tire |
| 4 bar | 58.015 psi | 400 kPa | 3.948 atm | EU pressure cooker; hydraulic pilot circuits |
| 6 bar | 87.023 psi | 600 kPa | 5.922 atm | EU water heater PRV; EU shop air entry |
| 8 bar | 116.030 psi | 800 kPa | 7.895 atm | EU standard factory air max output |
| 200 bar | 2,900.755 psi | 20,000 kPa | 197.385 atm | EU standard scuba fill (steel cylinder) |
| 232 bar | 3,364.876 psi | 23,200 kPa | 229.007 atm | EU HP scuba fill (high-pressure cylinder) |
Frequently Asked Questions About Bar to PSI Conversion
1 bar = 14.503773773020924… psi (non-terminating). Rounded: 14.5038 psi. Derivation: 1 bar = 100,000 Pa (exact BIPM definition) ÷ 6,894.75729316836 Pa/psi (NIST SP 811) = 14.5038. Quick rule: multiply bar by 14.5 for approximate psi. Also: 1 bar = 100 kPa exactly; 1 bar = 0.986923 standard atmospheres.
Multiply bar by 14.5038: psi = bar × 14.5038. Precisely: psi = bar × 100,000 / 6,894.75729316836. Or equivalently: psi = bar × 14.503773773… Quick mental estimate: multiply bar by 14.5, or by 15 for a slight overestimate. Reverse (psi to bar): bar = psi × 0.068948. Example: 2.2 bar × 14.5038 = 31.908 psi.
2 bar = 2 × 14.5038 = 29.008 psi = 200 kPa. This is close to the lower end of US passenger car tire pressure (most US cars specify 30-36 psi cold). A tire at 2 bar (29 psi) when the placard calls for 32 psi is slightly underinflated but not at TPMS alert level for most vehicles. EU compact car front tires are sometimes specified at 2.0 bar (29.0 psi), which is equivalent to 29 psi.
2.2 bar = 2.2 × 14.5038 = 31.908 psi, rounded to 32 psi. This is the single most common EU vehicle tire specification for front tires, appearing on Volkswagen, BMW, Audi, Mercedes, Peugeot, and Renault models. It converts almost perfectly to the most common US passenger car cold inflation pressure of 32 psi. When filling an EU vehicle at a US gas station: if the EU placard says 2.2 bar front, fill to 32 psi.
2.5 bar = 2.5 × 14.5038 = 36.259 psi, rounded to 36 psi. This is a common EU specification for SUV, crossover, and higher-load rear tires. European vehicles such as the BMW X5, Audi Q7, Volkswagen Tiguan, and Mercedes GLC frequently specify 2.5 bar (36 psi) for rear tires. Quick mental math: 2.5 bar × 14.5 = 36.25 ≈ 36 psi.
3 bar = 3 × 14.5038 = 43.511 psi = 300 kPa. This appears in several EU contexts: some commercial van and large SUV high-load tire specifications; EU residential water pressure in high-rise buildings (3-4 bar = 43.5-58.0 psi); EU steam cleaner low-output models; EU bicycle tire lower range for road tires. In the US: 43.5 psi is typical for full-size pickup truck rear tires (F-150 rear specification: 35-65 psi depending on load).
10 bar = 10 × 14.5038 = 145.038 psi = 1,000 kPa = 1 MPa (megapascal). This is a useful reference: 10 bar = 1 MPa exactly. It appears in EU industrial specifications for hydraulic pilot circuits, high-output compressors, and certain pneumatic actuator systems. Road bicycle tires at the high end of the range: 8-9 bar (116-130 psi). Hydraulic excavator pilot pressure circuits: 35-45 bar (508-653 psi) for most machines, above 10 bar.
6 bar = 6 × 14.5038 = 87.023 psi = 600 kPa. EU uses this as: maximum residential water pressure in many countries (vs 80 psi / 5.52 bar in the US); water heater pressure-relief valve (PRV) setpoint in EU models; entry-level factory pneumatic air line working pressure. In US context: 87 psi is within the residential water system range but above the US 80 psi (5.52 bar) UPC maximum, so EU appliances rated for 6 bar max can be protected by a standard US PRV set to 60-80 psi.
200 bar = 200 × 14.5038 = 2,900.755 psi (approximately 2,901 psi). This is the EU standard fill pressure for most recreational diving steel cylinders, governed by EN 144 and ISO 10462. The US standard recreational fill is 3,000 psi = 206.84 bar. So a European diver saying their tank is “full at 200 bar” has slightly less air than a US diver with a “full 3,000 psi fill”: 200 bar = 2,901 psi vs 3,000 psi. The EU HP fill standard (232 bar) = 3,364.9 psi is actually more than a US 3,000 psi fill. Diving computers with bar/psi switching let divers see either unit simultaneously.
4 bar = 4 × 14.5038 = 58.015 psi = 400 kPa. This appears in: EU electric pressure cooker high-pressure setting (some models); EU residential water supply upper comfortable range; EU steam cleaner operating pressure; hydraulic pilot circuit pressure for medium-duty machinery. In the US: 58 psi is toward the upper range of residential water pressure (ideal 40-60 psi per IRC P2903.3.1). 4 bar is also near the HVAC R-22 refrigerant low-side pressure at moderate ambient (58-68 psi).
8 bar = 8 × 14.5038 = 116.030 psi = 800 kPa. This is the maximum output pressure for many EU standard industrial air compressors and the commonly specified maximum inlet water pressure for EU-sourced commercial kitchen equipment, espresso machines, and industrial washers. US shop air compressors typically cut off at 125-135 psi (8.62-9.31 bar), so US plant air at 115-125 psi (7.93-8.62 bar) is right at or above the 8 bar (116 psi) maximum for some EU equipment.
1.5 bar = 1.5 × 14.5038 = 21.756 psi = 150 kPa. This represents dangerously low tire pressure for most passenger vehicles. The NHTSA TPMS mandate (FMVSS 138) requires alerting at 25% below the recommended cold inflation: for a 2.2 bar (31.9 psi) recommended tire, 25% below = 23.9 psi = 1.648 bar. A tire at 1.5 bar (21.8 psi) is significantly underinflated, risks bead unseating at highway speeds, and dramatically increases fuel consumption and tire wear. Inflate immediately if you see this reading on a tire pressure gauge.
100 bar = 100 × 14.5038 = 1,450.377 psi = 10,000 kPa = 10 MPa. This is a common pressure in: hydraulic power units for construction equipment and machine tools; professional water-jet cleaning systems (industrial pressure washers above 1,000 psi); hydraulic test bench equipment. A European hydraulic system rated at 100 bar working pressure (1,450 psi) is typically designed with a safety factor of 4:1, so a 400 bar (5,801 psi) burst rating on hydraulic hoses and fittings.
Gauge pressure (bar or psig) is measured relative to local atmospheric pressure. Absolute pressure (bara or psia) is measured from perfect vacuum. At sea level: absolute = gauge + 1.01325 bar (14.696 psi). Tire pressure is gauge: a car tire at 2.2 barg = 2.2 + 1.01325 = 3.21325 bara = 46.6 psia. Standard atmospheric pressure = 1.01325 bara = 14.696 psia = 0 barg = 0 psig. In European documentation, “bar” without a suffix typically means gauge pressure in process and pneumatic contexts. In scientific and diving contexts, “bar” often means absolute. The US uses “psi” for gauge (psig) and “psia” for absolute. If not labeled, most equipment pressures are gauge.
7 bar = 7 × 14.5038 = 101.527 psi = 700 kPa. This falls just above the US 80 psi (5.52 bar) residential water maximum. EU commercial espresso machines typically operate at 8-9 bar (116-130 psi) boiler pressure, with pump pressure at 9 bar (130.5 psi) for extraction. EU dishwashers and commercial washers sometimes specify maximum inlet at 7 bar (101.5 psi), meaning a US PRV set to 80 psi (5.52 bar) provides safe protection. Check the appliance nameplate: if it reads “Max Inlet Pressure 7 bar (700 kPa)”, a US supply at 60-80 psi is within spec.
Yes, this converter uses Big.js arbitrary-precision arithmetic and exact definitions from both BIPM and NIST SP 811. 1 bar = 100,000 Pa exactly (BIPM). 1 psi = 6,894.75729316836 Pa (from exact NIST chain: 1 lbf = 0.45359237 kg × 9.80665 m/s² = 4.44822162 N; 1 in² = 0.00064516 m²). Therefore 1 bar = 100,000 / 6,894.757 = 14.5037737730… psi. Verified values: 2.2 bar = 31.908 psi; 2.5 bar = 36.259 psi; 8 bar = 116.030 psi; 200 bar = 2,900.755 psi; 1.01325 bar = 14.696 psi (1 atm). Sources: BIPM.org; NIST SP 811.
Related Pressure, Speed, and Engineering Calculators
Legal Disclaimer and Editorial Transparency
This bar to psi converter is for educational and informational purposes only. The conversion factor 1 bar = 14.503773773… psi is derived from the BIPM definition of bar (100,000 Pa exactly) and NIST SP 811 definition of psi (1 lbf = 0.45359237 kg × 9.80665 m/s²; 1 in² = 0.0254² m²; 1 psi = 6,894.757 Pa). All results use Big.js arbitrary-precision arithmetic to prevent floating-point rounding errors. Tire pressure recommendations (2.2 bar, 2.5 bar) are illustrative of common EU specifications; always use your vehicle’s door-jamb placard for actual tire inflation. TPMS alert thresholds reflect NHTSA FMVSS 138 (25% below recommended) for US vehicles after September 2007. Pressure cooker guidance reflects general operating pressures; always follow manufacturer instructions and USDA guidelines for food safety. Scuba fill pressures (200 bar, 232 bar) are reference values; follow your certifying agency (PADI, SSI, NAUI) training and equipment manufacturer’s fill specifications, and comply with DOT cylinder inspection and hydrostatic test requirements. Industrial pressure values (ISO 4414, ASME, SAE) are cited for educational context; qualified engineers should design and certify pressure systems. Barometric pressure data is educational; for aviation, always use official NWS/FAA ATIS broadcasts and certified altimeter settings. Content reviewed by the USCalculators.com editorial team. References: BIPM.org; NIST SP 811; NHTSA FMVSS 138; ISO 4414; SAE J517; USDA NCHFP; FAA 14 CFR Part 91.