📏 Math and Unit Conversion

Inches to CM Converter: Single Distance, US to International Shoe Size Mode, and Batch Conversion

Three modes: convert inches to centimeters with full output (cm, mm, meters, feet, yards), use shoe size mode to convert US men’s and women’s sizes to cm foot length plus EU, UK, and Japanese equivalents, or batch-convert up to 20 values. Exact: 1 inch = 2.54 cm. PDF and WhatsApp share included.

Inches to CM Exact US Shoe Size to EU, UK, JP CM Foot Length Reference Men’s and Women’s Sizes Batch up to 20 Values PDF and WhatsApp
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Inches to CM Converter

in
Enter any inch value (decimals OK). Key: 1 in = 2.54 cm; 6 in = 15.24 cm; 12 in = 30.48 cm = 1 ft; 36 in = 91.44 cm = 1 yd; 60 in = 152.4 cm = 5 ft.

Conversion Result

0 centimeters
0 MM / CM Foot
0 Meters / UK Size
0 Feet / JP Size

Formula Used

Why Inches to CM Matters for Shoe Sizes, Paper Formats, and International Shopping

The inch-to-centimeter conversion shows up in more everyday American situations than most people realize. The most practically important for US consumers is international shoe sizing. American shoes use a numbered size system (men’s 7 through 15, women’s 5 through 12) that is not used by European, British, or Japanese shoe retailers. Someone buying shoes from a Spanish brand on ZARA.com, a German brand on Zalando, an Italian brand on Farfetch, or a Japanese brand on Rakuten needs to convert their US shoe size to the local size system. This converter’s shoe mode solves that directly: enter your US size and gender, get your exact cm foot length plus EU, UK, and Japanese size in one step.

The second major use case is paper and document sizes. US standard paper (Letter: 8.5 x 11 inches, Legal: 8.5 x 14 inches) differs from international A4 (210 x 297 mm = 8.27 x 11.69 inches). Converting: 8.5 inches = 21.59 cm; 11 inches = 27.94 cm; 14 inches = 35.56 cm. Understanding these conversions matters when printing international documents, configuring printers for international audiences, or specifying dimensions for graphic design work that will be printed in both US and international markets.

The third frequent use case is screen and monitor sizes. The US and global tech industry specifies screen diagonals in inches: 15.6-inch laptop, 27-inch monitor, 65-inch TV. International specs, product listings, and room planning tools sometimes request these in centimeters. 15.6 inches = 39.62 cm; 27 inches = 68.58 cm; 65 inches = 165.10 cm. The single-mode conversion handles these immediately, and the batch mode allows converting a full list of screen sizes in one step.

2.54 cm Exact centimeters per inch. 1 inch = 2.54 cm exactly. Defined by the International Yard and Pound Agreement, 1959. All inch-to-cm math derives from this single definition.
US Size 9 Most common US men’s shoe size sold in the United States. US Men’s 9 = EU 42-43 = UK 8.5 = approximately 25.7 cm foot length. Women’s most common: US 7 = EU 37 = UK 4.5 = 23.5 cm.
30.48 cm Exact centimeters per foot. 12 inches x 2.54 = 30.48 cm. The metric equivalent of 1 foot. Note: a 30 cm ruler is 11.811 inches, not quite a full foot.

How Does This Three-Mode Inches to CM Converter Work?

Mode 1: Single Inches to CM

Enter any inch value (whole numbers or decimals) and get the exact centimeter equivalent, plus millimeters, meters, feet, and yards. The bar chart compares the user’s value to reference points at 1, 6, 12, and 36 inches in cm. Context notes appear for notable values: 1 in = 2.54 cm exactly; 6 in = 15.24 cm (half a foot); 8.5 in = 21.59 cm (US Letter paper short side); 11 in = 27.94 cm (US Letter paper long side); 12 in = 30.48 cm (exactly 1 foot); 36 in = 91.44 cm (exactly 1 yard); 60 in = 152.4 cm (5 feet); 72 in = 182.88 cm (6 feet).

Mode 2: US to International Shoe Size Mode

Select your gender (Men’s or Women’s), enter your US shoe size (half sizes supported from 5 to 15 for men’s, 5 to 12 for women’s), and get your cm foot length plus EU, UK, and Japanese sizes. The bar chart displays your size alongside adjacent sizes in cm foot length, with your size highlighted in green. The PDF export includes the complete men’s and women’s shoe size conversion tables for offline reference.

Mode 3: Batch Inches to CM

Enter up to 20 inch values (one per line or comma-separated, decimals accepted) and get a table of exact cm (4 decimal places), mm, and feet for each. Useful for converting a list of screen sizes, lumber dimensions, fabric measurements, or any set of inch-based specifications to centimeters at once.

Three Real Examples: International Shoe Shopping, US Paper in CM, and TV Screen Measurement

Example 1: Converting US Shoe Size to EU and CM for International Purchase

Shoe Mode: US Men’s 10 = EU 44 = UK 9.5 = JP 28.0 cm = 26.7 cm foot length

A US man wears a size 10 shoe and is ordering from an Italian footwear brand that uses EU sizing. The product page lists sizes in EU only: EU 43, EU 44, EU 45. Which size should he order?

US Men’s 10 corresponds to a foot length of approximately 26.7 cm and EU size 44. US Men’s 10.5 corresponds to EU 44.5. He should order EU 44 for a standard fit.

The cm foot length is the most accurate bridge between sizing systems because it directly measures the physical foot rather than using an arbitrary size number. The EU sizing system is based on “Paris points,” where 1 Paris point = 2/3 of a centimeter. EU 44 corresponds to a foot length of roughly 27.3 cm in the EU calculation (44 x 2/3 = 29.33 cm last length, which typically accommodates a 26.7 cm foot with standard shoe allowance). Different brands may run slightly narrow or wide, but EU 44 is the universally accepted equivalent of US Men’s 10. The PDF export from shoe mode includes the complete US-to-EU-to-cm table for both men’s and women’s sizes, which is useful to have on hand when shopping at international retailers like ASOS (UK), Zalando (Germany), Farfetch (Portugal/international), or when visiting stores in Europe or Japan. The American Academy of Orthopaedic Surgeons at AAOS.org recommends measuring foot length in both inches and cm when purchasing footwear online to ensure the best fit.

Example 2: Converting US Letter Paper Dimensions to CM for International Printing

Batch Mode: 8.5 in = 21.59 cm; 11 in = 27.94 cm; 14 in = 35.56 cm

A graphic designer is creating a document that needs to be printed in both the US (on Letter-size paper) and internationally (on A4 paper, 21.0 x 29.7 cm). She needs to know the US Letter dimensions in cm to adjust the design for the international version.

US Letter paper: 8.5 x 11 inches = 21.59 x 27.94 cm. International A4: 21.0 x 29.7 cm. Differences: width 0.59 cm wider on Letter; height 1.76 cm shorter on Letter than A4. US Legal: 8.5 x 14 in = 21.59 x 35.56 cm.

The differences between US Letter and A4 are not large but matter for document layout. The A4 sheet is taller and slightly narrower than US Letter. A document with 1-inch (2.54 cm) margins on Letter paper has a text area of 6.5 x 9 inches = 16.51 x 22.86 cm. The same margins on A4 leave 6.27 x 10.27 inches = 15.93 x 26.09 cm of text area. A designer converting a US Letter document to A4 needs to check that headers, footers, and page breaks do not shift awkwardly in the extra vertical space. The US Government Publishing Office (GPO) at GPO.gov uses US Letter for federal publications; international counterparts use A4. Understanding both dimensions in both inches and cm is essential for cross-border document production.

Example 3: Converting TV and Monitor Screen Sizes to CM for Room Planning

Batch Mode: 55 in = 139.70 cm; 65 in = 165.10 cm; 75 in = 190.50 cm

A homeowner is planning a living room layout using a metric-based furniture planning tool (such as IKEA’s room planner, which uses cm). He wants to see how three TV sizes (55, 65, and 75 inches) compare in centimeters to determine which fits the room and TV stand.

55 in = 139.70 cm (diagonal). 65 in = 165.10 cm (diagonal). 75 in = 190.50 cm (diagonal). Note: these are screen diagonal measurements. Actual TV width is approximately: 55 in TV = ~48.5 in wide = ~123 cm. 65 in TV = ~57 in wide = ~145 cm. 75 in TV = ~66 in wide = ~168 cm.

The actual width of a widescreen (16:9) TV is approximately 87% of the diagonal measurement. So a 65-inch TV: 65 x 0.87 = 56.55 inches wide = 143.6 cm wide. For a TV stand that is 60 inches (152.4 cm) wide, the 65-inch TV (143.6 cm wide) fits with about 8.8 cm of clearance on each side. The 75-inch TV (168 cm wide) would overhang. The batch mode converts all three diagonal measurements at once, and the homeowner can then apply the 87% ratio to get the actual widths. The Consumer Electronics Association’s display sizing standards reference diagonal measurements exclusively, which is why the inches-to-cm conversion is the standard step in international home electronics shopping and room planning.

US Men’s and Women’s Shoe Sizes in Inches, CM, EU, UK, and Japanese Sizes

The shoe size conversion tables below are based on standard foot length measurements. The cm column represents the recommended foot length in centimeters for each US size. The EU column uses the standard European Paris-point system. UK sizes for men are typically 0.5 less than US men’s sizes; for women, UK sizes are typically 2.5 less than US women’s sizes. Japanese sizes are given in centimeters of foot length (the most direct measurement system).

Men’s Shoe Sizes: US to CM, EU, UK, and Japanese

US Men’sFoot Length (cm)Foot Length (in)EU SizeUK SizeJapanese (cm)
623.7 cm9.33 inEU 38UK 5.5JP 24
6.524.1 cm9.49 inEU 39UK 6JP 24.5
724.4 cm9.61 inEU 40UK 6.5JP 25
7.524.8 cm9.76 inEU 40.5UK 7JP 25
825.4 cm10.00 inEU 41UK 7.5JP 26
8.525.7 cm10.12 inEU 42UK 8JP 26.5
925.7 cm10.12 inEU 42.5UK 8.5JP 27
9.526.0 cm10.24 inEU 43UK 9JP 27.5
1026.7 cm10.51 inEU 44UK 9.5JP 28
10.527.0 cm10.63 inEU 44.5UK 10JP 28.5
1127.3 cm10.75 inEU 45UK 10.5JP 29
11.527.6 cm10.87 inEU 45.5UK 11JP 29.5
1228.3 cm11.14 inEU 46UK 11.5JP 30
1329.0 cm11.42 inEU 47UK 12.5JP 31
1429.6 cm11.65 inEU 48UK 13.5JP 31.5
1530.3 cm11.93 inEU 49UK 14.5JP 32

Women’s Shoe Sizes: US to CM, EU, UK, and Japanese

US Women’sFoot Length (cm)Foot Length (in)EU SizeUK SizeJapanese (cm)
522.1 cm8.70 inEU 35UK 2.5JP 22.5
5.522.4 cm8.82 inEU 35.5UK 3JP 23
622.9 cm9.02 inEU 36UK 3.5JP 23.5
6.523.2 cm9.13 inEU 36.5UK 4JP 23.5
723.5 cm9.25 inEU 37UK 4.5JP 24
7.523.8 cm9.37 inEU 37.5UK 5JP 24
824.1 cm9.49 inEU 38UK 5.5JP 24.5
8.524.5 cm9.65 inEU 38.5UK 6JP 25
924.8 cm9.76 inEU 39UK 6.5JP 25.5
9.525.1 cm9.88 inEU 39.5UK 7JP 25.5
1025.4 cm10.00 inEU 40UK 7.5JP 26
10.525.7 cm10.12 inEU 40.5UK 8JP 26.5
1126.0 cm10.24 inEU 41UK 8.5JP 26.5
1226.7 cm10.51 inEU 42UK 9.5JP 27.5

Important note on shoe sizing: these tables represent general industry averages. Individual brands may size differently. Italian and Spanish luxury shoe brands (Salvatore Ferragamo, Manolo Blahnik, etc.) often run narrow and may require going up half a size. German and British brands tend to run true to size. Japanese sizes represent foot length in cm directly, making them the most precise cross-border sizing system. When in doubt, measure your foot length in centimeters (heel to longest toe while standing) and compare directly to the cm column in the table above. The American Orthopaedic Foot and Ankle Society at AOFAS.org recommends measuring feet in the afternoon (when feet are at their largest due to daily swelling) for the most accurate fit measurement.

What Is the Formula to Convert Inches to Centimeters?

Multiply by 2.54. Formula: cm = inches x 2.54. This is exact. The inch is defined as exactly 2.54 centimeters under the international agreement of 1959. Multiplying any inch value by 2.54 gives the exact centimeter equivalent without any rounding error in the fundamental conversion factor itself.

Common exact values: 1 in = 2.54 cm. 2 in = 5.08 cm. 6 in = 15.24 cm. 12 in = 30.48 cm (1 foot). 18 in = 45.72 cm. 24 in = 60.96 cm. 36 in = 91.44 cm (1 yard). 60 in = 152.4 cm (5 feet). 72 in = 182.88 cm (6 feet). For mental math: every inch is approximately 2.5 cm (actual: 2.54 cm, so this approximation introduces a 1.6% error). A more precise mental shortcut: multiply by 2.5 and add 1.6% of the result. Or: for every 10 inches, add 25.4 cm. NIST confirms the exact definition at NIST.gov.

Expert Tips for Inches-to-CM Conversions in Shoes, Tech, and Daily Life

Tip 1: Measure Your Foot in CM Before Ordering International Shoes

The most reliable approach to ordering shoes from international retailers is to measure your actual foot length in centimeters rather than relying solely on your US size. To measure: stand on a piece of paper, trace the outline of your foot with a pencil held vertically, then measure the distance from the heel to the tip of the longest toe with a ruler or measuring tape in cm. Repeat for both feet and use the larger measurement. Compare this cm measurement directly to the foot length column in the shoe size table above. If your foot measures 26.5 cm, you sit between US Men’s 9 (25.7 cm) and US Men’s 10 (26.7 cm), and you would likely order EU 43 or 44 depending on the brand’s width and construction. Japanese shoe sizes (listed in cm) are the most precise because they directly reflect foot length rather than using an arbitrary numbering system: a Japanese size 26.5 literally means a 26.5 cm foot. This direct cm measurement is also the sizing method recommended for athletic shoes where precise fit affects performance, such as running and hiking footwear.

Tip 2: The 2.5 Approximation and When to Use the Exact Formula

For quick mental math, 1 inch is approximately 2.5 cm (the exact value is 2.54 cm). This approximation works well for rough estimates but introduces a 1.6% cumulative error that matters in specific contexts. For a 1-inch measurement: 2.5 cm vs actual 2.54 cm (off by 0.04 cm = 0.4 mm, fine for most purposes). For a 12-inch measurement: 30 cm vs actual 30.48 cm (off by 0.48 cm = 4.8 mm, noticeable in carpentry or tailoring). For a 72-inch measurement (6 feet): 180 cm vs actual 182.88 cm (off by 2.88 cm = nearly 1.1 inches, significant for height measurement). The rule is: for approximate estimates like screen sizes or room dimensions, the 2.5 cm mental shortcut is fine. For precise work like shoe sizing, tailoring measurements, technical specifications, woodworking cuts, or medical documentation, always use the exact 2.54 cm factor or use this calculator. The difference between 27 cm and 27.94 cm (11 inches) is nearly 1 cm, which matters for inseam length in tailored trousers.

Tip 3: Understanding Why US Shoe Sizes Use a Different System from EU

American shoe sizes trace back to a 19th-century English system using “barleycorns” as the unit (1 barleycorn = 1/3 inch). US shoe sizes were originally calibrated so that a child’s size 0 corresponded to a 3.3-inch (8.5 cm) foot length, with each size adding 1/3 inch (0.847 cm). Men’s and women’s sizes diverge because they historically used different starting points. European sizes use the “Paris point” system where 1 Paris point = 2/3 cm (6.67 mm). EU sizes represent the shoe’s last length (internal length) in Paris points, which includes a toe allowance beyond the actual foot length. An EU 44 last = 44 x 2/3 cm = 29.33 cm, accommodating a 26.7-27 cm actual foot. This is why EU sizes track closely with foot length in cm but are not identical to them. Japanese sizes simply list the foot length in cm (sometimes with a half-cm increment system), which is the most internationally intuitive format. Australian sizes match US men’s sizes; UK sizes are 0.5 smaller than US men’s and 2.5 smaller than US women’s. When shopping online internationally, the cm foot length measurement bypasses all of these different systems and gives retailers and consumers a universal reference point.

Common Inches to CM Reference Values

InchesCMContext
0.25 in0.635 cm1/4 inch; common US hardware and woodworking measurement
0.5 in1.27 cm1/2 inch; standard US pipe increment
1 in2.54 cmExactly 1 inch; US Men’s shoe size adds roughly 0.8 cm per full size
2 in5.08 cmStandard US lumber nominal width (2×4 board)
3 in7.62 cmStandard ice hockey puck diameter
4 in10.16 cmStandard US modular brick depth
6 in15.24 cmHalf a 12-inch ruler; US Men’s shoe 6 foot length ~9.3 in
8.5 in21.59 cmUS Letter paper width (8.5 x 11 in)
11 in27.94 cmUS Letter paper height; US Men’s 11 shoe foot ~10.75 in
12 in30.48 cmExactly 1 foot; 30 cm ruler is slightly shorter at 11.81 in
17 in43.18 cmStandard laptop screen diagonal
24 in60.96 cmCommon desktop monitor size
27 in68.58 cmPopular professional monitor size
36 in91.44 cmExactly 1 yard; standard US door width
55 in139.70 cmCommon living room TV diagonal
60 in152.40 cmExactly 5 feet; average US adult female height
65 in165.10 cmLarge living room TV diagonal; ~57 in wide = 145 cm
69 in175.26 cmAverage US adult male height (5’9″)
72 in182.88 cmExactly 6 feet

US Paper Sizes in Inches and Centimeters

Paper SizeInchesCMCommon Use
US Letter8.5 x 11 in21.59 x 27.94 cmStandard US office, home printing
US Legal8.5 x 14 in21.59 x 35.56 cmLegal documents, contracts
US Tabloid11 x 17 in27.94 x 43.18 cmNewspapers, large format printing
Half Letter5.5 x 8.5 in13.97 x 21.59 cmNotepads, booklets
Index Card (3×5)3 x 5 in7.62 x 12.70 cmFlashcards, recipe cards
Index Card (4×6)4 x 6 in10.16 x 15.24 cmStandard index cards, photo prints
Photo (4×6)4 x 6 in10.16 x 15.24 cmStandard photo print size
Photo (5×7)5 x 7 in12.70 x 17.78 cmPortrait photo frame standard
Photo (8×10)8 x 10 in20.32 x 25.40 cmStandard US photo frame size

Frequently Asked Questions About Inches to CM

1 inch = 2.54 cm exactly. This is the exact international legal definition, established in 1959. Formula: cm = inches x 2.54.
1 inch = 2.54 cm exactly. Formula: 1 x 2.54 = 2.54 cm.
2 inches = 5.08 cm. Formula: 2 x 2.54 = 5.08 cm.
3 inches = 7.62 cm. Formula: 3 x 2.54 = 7.62 cm.
4 inches = 10.16 cm. Formula: 4 x 2.54 = 10.16 cm.
5 inches = 12.70 cm. Formula: 5 x 2.54 = 12.70 cm.
6 inches = 15.24 cm. Formula: 6 x 2.54 = 15.24 cm. Six inches is exactly half a 12-inch ruler.
10 inches = 25.40 cm. Formula: 10 x 2.54 = 25.40 cm.
12 inches = 30.48 cm = exactly 1 foot. Formula: 12 x 2.54 = 30.48 cm.
0.5 inches = 1.27 cm. Formula: 0.5 x 2.54 = 1.27 cm. Half an inch is 12.7 mm.
36 inches = 91.44 cm = exactly 1 yard. Formula: 36 x 2.54 = 91.44 cm.
7 inches = 17.78 cm. Formula: 7 x 2.54 = 17.78 cm.
8 inches = 20.32 cm. Formula: 8 x 2.54 = 20.32 cm.
9 inches = 22.86 cm. Formula: 9 x 2.54 = 22.86 cm.
11 inches = 27.94 cm. Formula: 11 x 2.54 = 27.94 cm. Also the long dimension of US Letter paper (8.5 x 11 inches).
60 inches = 152.40 cm = exactly 5 feet. Formula: 60 x 2.54 = 152.40 cm.
72 inches = 182.88 cm = exactly 6 feet. Formula: 72 x 2.54 = 182.88 cm.
69 inches = 175.26 cm. Formula: 69 x 2.54 = 175.26 cm. 69 inches is exactly 5 feet 9 inches, the average height of US adult males according to CDC data.
0.25 inches (1/4 inch) = 0.635 cm = 6.35 mm. Formula: 0.25 x 2.54 = 0.635 cm. Quarter-inch is a very common US hardware, woodworking, and baking measurement.
1.5 inches = 3.81 cm. Formula: 1.5 x 2.54 = 3.81 cm. One and a half inches is 38.1 mm.