What is the 70/30 rule for raised bed soil?

Fill raised beds with 70% quality topsoil or garden mix and 30% compost. The topsoil provides structure and the compost adds nutrients and drainage. Never use 100% topsoil — it compacts and suffocates roots.

Free US Topsoil Calculator

Topsoil Calculator — Cubic Yards, Bags, Weight & Cost

Q: How many cubic yards of topsoil do I need for 1,000 sq ft?

At 4 inches deep: 12.3 yd³. At 6 inches: 18.5 yd³. At 1 inch topdressing: 3.1 yd³. Always add 10-15% for settling.

Q: How many 40-pound bags of topsoil per cubic yard?

By volume: approximately 36 bags of 40 lb topsoil (at 0.75 cu ft per bag) per cubic yard. By weight: 50 bags per cubic yard at 2,000 lbs/yd³.

Q: Is it cheaper to buy topsoil in bulk or bags?

Bulk is dramatically cheaper. Bagged topsoil costs $240-360 per cubic yard equivalent. Bulk delivered topsoil runs $35-80 per cubic yard — roughly 3-7× less expensive. For any project over 0.5 yd³, bulk delivery wins.

Get exact cubic yards, all bag sizes, raised bed mix recipe (70/30 rule), bag vs. bulk cost comparison, truck payload warning, and a branded PDF report. Works for new lawns, raised beds, garden beds, topdressing, and yard leveling.

Enter Your Project Details

Step 1 — Project Type

Step 2 — Soil Type

Step 3 — Depth & Settling

Soil Depth

inches

Garden bed: 4–6 in for annuals & vegetables

Settling Allowance

15%

Raised Bed Mix Recipe (70/30 Rule)

Topsoil (70%)—

Compost (30%)—

Total Volume—

Step 4 — Area Dimensions

1 Area 1

Shape

Rectangle / Square Circle Triangle

Width (ft)

Length (ft)

Step 5 — Pricing & Delivery

Bulk Price Per yd³

Price Per 40 lb Bag

Pickup Truck Payload

Half-ton (1,000 lb safe) 3/4-ton (1,500 lb safe) 1-ton truck (2,000 lb safe) No truck / delivery

Delivery Minimum (yd³)

No minimum 1 yd³ minimum 2 yd³ minimum 5 yd³ minimum

Your Results

Select your project type, enter dimensions, and click Calculate Topsoil to see cubic yards, bags, weight, and cost comparison.

How Much Topsoil Do You Actually Need? A Depth Guide for Every American Yard Project

The single most common topsoil mistake American homeowners make is not knowing how deep to go. Put down too little — say, 2 inches for a new lawn — and the grass roots hit compacted subsoil within one season, leaving you with thin, drought-stressed turf no matter how much you fertilize. Go too deep for a topdressing project and you smother the existing grass. Every topsoil application has a sweet spot, and that depth is determined by what you are trying to accomplish, not by how much material happens to be on the pallet at Home Depot.

Here is the depth guide that landscape professionals in the US use for every project type:

New Lawn Installation — 4 to 6 Inches

A new lawn needs enough topsoil for grass roots to establish deeply before they hit the compacted subsoil layer. The University of Minnesota Extension recommends a minimum of 4 inches of quality topsoil for turfgrass establishment, with 6 inches being the standard for premium lawns in northern states where winters are severe. At 6 inches deep, a 1,000 sq ft lawn requires approximately 18.5 cubic yards of topsoil — that is a significant order, and always a bulk delivery job.

Topdressing an Existing Lawn — ½ to 2 Inches

Topdressing is the annual practice of spreading a thin layer of screened topsoil or compost over an existing lawn to improve soil biology, fill in low spots, and support overseeding. The key word is thin. More than ½ inch per application smothers the existing grass. Most lawn care professionals apply ¼ to ½ inch per topdressing session, repeating once or twice per season if needed. For a 5,000 sq ft lawn at ½ inch depth, you need only about 7.7 cubic yards — manageable with a bulk delivery and a wheelbarrow.

Raised Garden Beds — Fill the Entire Box

Raised beds are different from every other topsoil application because you are not adding a layer on top of existing soil — you are filling the entire box. A standard 4 × 8 × 1 foot raised bed requires 32 cubic feet = 1.19 cubic yards. A deeper 4 × 8 × 12 inch bed needs 1.19 × 1.0 = same, because depth is 1 foot. Wait — that is the same number. Yes, because the box dimensions already include the depth. Our raised bed mode calculates the full box volume, not a coverage layer.

The 70/30 Raised Bed Mix Rule: Professional gardeners and master gardeners across the US recommend filling raised beds with a blend of 70% quality topsoil (or garden mix) and 30% compost. The topsoil provides structure and weight, the compost provides nutrients, drainage improvement, and the biological activity that feeds your vegetables. Never fill a raised bed with 100% topsoil — it compacts like concrete when watered repeatedly and suffocates root systems.

In-Ground Garden Beds — 4 to 6 Inches

For planting new annual flower beds, perennial borders, or vegetable gardens in the ground, tilling in 4 to 6 inches of quality topsoil or garden mix creates the fluffy, well-drained planting zone that root systems need. Till the existing soil to 6–8 inches, add your topsoil, and re-till to blend. This is different from a new lawn — garden bed plants have much deeper root systems than turf, so the investment in deeper soil preparation pays dividends for years.

Yard Leveling / Low Spot Repair — 2 to 6 Inches

Low spots in yards collect standing water after every rain and eventually kill turf, attract mosquitoes, and undermine foundations. Filling them requires enough topsoil to grade slightly above the surrounding area, accounting for 10–15% settling. For shallow low spots (under 2 inches), topdressing with screened topsoil works well. For deeper voids, use fill dirt for the base, cap with a 2-inch layer of screened topsoil, and reseed. Never use mulch to fill low spots — it decomposes and the void returns.

Project Type	Recommended Depth	Settling Allowance	Best Soil Type
New Lawn	4–6 inches	15–20%	Screened Topsoil
Topdressing	¼–1 inch	10%	Screened Topsoil or Compost
Raised Garden Bed (full fill)	Full box depth (6–12 in)	20–25%	Garden Mix + Compost (70/30)
In-Ground Garden Bed	4–6 inches	15%	Garden Mix or Screened Topsoil
Yard Leveling	2–6 inches (varies)	15%	Fill Dirt (base) + Screened Topsoil (cap)

Understanding Topsoil Types — What the Big-Box Stores and Landscape Yards Are Actually Selling

Walk into a Lowe’s garden center and you will see bags labeled “Premium Topsoil,” “Garden Soil,” “Potting Mix,” and “Compost” all sitting next to each other. At a landscape supply yard, you will hear terms like “screened topsoil,” “unscreened fill,” and “amended garden mix.” Here is what each one actually means for your project:

Screened Topsoil — The All-Purpose Standard

Screened topsoil has been run through a rotary screen to remove large rocks, roots, and debris, leaving a fine, consistent texture. It is the go-to for lawns, flower beds, and grading. Standard density is approximately 2,000 lbs per cubic yard. Premium screened topsoil from reputable landscape suppliers will have documented organic matter content (aim for 5–10%) and a pH in the 6.0–7.0 range appropriate for most American lawn and garden plants. Ask for a soil test result before buying large quantities.

Unscreened Topsoil — Budget Grade for Grading

Unscreened topsoil may contain pebbles, small rocks, and clumps of clay — it has not been sifted. It is cheaper per yard and perfectly appropriate for rough grading, filling large low spots where you will cap with screened topsoil, or building up grade behind a retaining wall. Do not plant directly into unscreened topsoil without amending it — it will compact and drain poorly.

Garden Mix / Planting Mix — The Raised Bed Champion

Garden mix is a pre-blended product typically consisting of topsoil, compost, and sometimes perlite or aged bark fines. It is lighter than pure topsoil (around 1,600 lbs per cubic yard), drains better, and has higher organic matter content right out of the bag. For raised beds, it is a premium but worthwhile upgrade over raw topsoil. At landscape supply yards, it may be called “garden blend,” “raised bed mix,” or “premium planting mix.”

Fill Dirt — Not Topsoil, Despite What Some Sellers Imply

Fill dirt is subsoil — it comes from below the topsoil layer and has minimal organic content. It compacts well and is great for structural fill under driveways, around foundations, and for large grading projects where you need stable, compactable material. At 2,200 lbs per cubic yard, it is heavier and denser than topsoil. Never use fill dirt as a planting medium — plants will struggle and likely die in the low-oxygen, low-nutrient environment.

Three Real American Topsoil Projects, Calculated Step by Step

Example 1: Columbus, Ohio — New Backyard Lawn from Scratch

Midwest climate, new construction, screened topsoil for turfgrass

Tom and Amy just closed on a new construction home in Westerville. The builder graded the yard and left compacted subsoil — no topsoil at all. Their backyard measures 50 × 40 feet. They want 6 inches of screened topsoil before seeding a Kentucky Bluegrass lawn. Their local landscape supply company charges $42 per yard delivered.

Input	Value
Backyard area	50 × 40 = 2,000 sq ft
Depth	6 inches
Raw volume	2,000 × 6 ÷ 324 = 37.04 yd³
With 15% settling	42.6 yd³ → order 43 yards
Weight at 2,000 lbs/yd³	43 tons (86,000 lbs)
Bulk cost (43 × $42)	$1,806
Bag equivalent (40 lb bags)	2,150 bags × $5.98 = $12,857

✅ At 43 yards, this is a 3–4 dump truck delivery job. Buying in bags would cost over 7× more. Tom and Amy order 43 yards of screened topsoil delivered in two loads, budgeting $2,000 including delivery fees. The bag equivalent would be financially absurd at $12,857.

Example 2: Denver, Colorado — Three 4×8 Raised Vegetable Beds

High-altitude climate, raised bed fill, 70/30 garden mix + compost

Lisa is building three 4 × 8 × 12-inch raised cedar beds in her Denver backyard for growing tomatoes, peppers, and herbs. She wants to use the 70/30 mix: 70% premium garden mix, 30% compost. Her local Tagawa Gardens nursery sells garden mix at $58/yard and compost at $48/yard.

Input	Value
Three beds (each 4 × 8 × 1 ft)	96 sq ft × 1 ft = 96 cu ft total
Volume per bed	32 cu ft = 1.19 yd³
Total volume (3 beds)	3.56 yd³
With 20% settling	4.27 yd³ total
Garden mix (70%)	2.99 yd³ × $58 = $173.42
Compost (30%)	1.28 yd³ × $48 = $61.44
Total soil cost	$234.86

✅ Lisa orders 3 yards of garden mix and 1.5 yards of compost (delivery minimum). Total material budget under $240. Our raised bed 70/30 calculator shows her exactly how much of each material to order — no guesswork.

Example 3: Atlanta, Georgia — Lawn Topdressing + Overseeding

Piedmont South, existing lawn renovation, screened topsoil topdressing

James has a 3,000 sq ft Bermuda grass lawn in Marietta that has developed thin spots and slight unevenness over 8 years. His lawn care company recommends aerating, then topdressing with ½ inch of screened topsoil, followed by Bermuda grass seed. Local topsoil is $38 per yard; 40 lb bags at Home Depot are $5.98 each.

Input	Value
Lawn area	3,000 sq ft
Depth (topdressing)	0.5 inch
Raw volume	3,000 × 0.5 ÷ 324 = 4.63 yd³
With 10% settling	5.09 yd³ → order 5.5 yards
Weight (5.5 × 2,000 lbs)	11,000 lbs (5.5 tons)
Bulk cost (5.5 × $38)	$209
40 lb bags needed	275 bags × $5.98 = $1,645

✅ James orders 5.5 yards of screened topsoil delivered ($209 + $65 delivery = $274 total). The bag equivalent of 275 bags would cost $1,645 — nearly 6× more. Even for a half-inch topdressing on a standard Atlanta lawn, bulk wins by a landslide.

Three Expert Tips for Buying and Applying Topsoil

Always Add a 15% Settling Allowance to Your Order

Topsoil settles significantly after delivery — particularly in raised beds and new lawn installations where it is loose and not yet compacted. A freshly placed 6-inch layer will settle to roughly 5 inches within one watering season. Ordering 15% extra (the default in our calculator) ensures you end up at your target depth after settling, not under it. For compost-rich mixes, bump the allowance to 20–25% — compost compresses more than mineral soil as it integrates with existing ground.

Ask for a Soil Test Before Buying Premium Topsoil

Reputable landscape supply companies in the US can provide a basic soil test result for their screened topsoil — showing pH, organic matter percentage, and sometimes nutrient levels. A quality topsoil should have a pH between 6.0 and 7.0, organic matter above 4–5%, and be free of weed seeds (ask if the topsoil is heat-treated or from a weed-free source). Buying cheaper topsoil loaded with weed seeds will cost you far more in herbicide and labor over the next several years.

Plan Your Delivery Access Before You Order

A full dump truck of topsoil weighs 10–14 tons and needs solid ground to maneuver. Before ordering, check whether your driveway can handle the weight (most residential concrete can, but asphalt may crack under heavy axle loads in warm weather), and identify where the driver will deposit the load. If the truck cannot get close to the work area, you will be moving topsoil with a wheelbarrow from the street — a 10-yard order can require 50–70 wheelbarrow loads. Many suppliers also offer smaller “mini-dump” delivery trucks for tight residential access situations.

Frequently Asked Questions About Topsoil Calculation

How many cubic yards of topsoil do I need for 1,000 sq ft?+

It depends on depth. At 4 inches: 1,000 × 4 ÷ 324 = 12.3 yd³. At 6 inches: 18.5 yd³. At 1 inch (topdressing): 3.1 yd³. Always add 10–15% for settling. For a standard new lawn at 4 inches with 15% settling: order about 14 yards. For topdressing at ½ inch with 10% settling: about 1.7 yards.

How many 40-pound bags of topsoil per cubic yard?+

One cubic yard of topsoil weighs approximately 2,000 lbs. At 40 lbs per bag, you need 50 bags per cubic yard. At 0.75 cu ft per 40 lb bag, that works out to 36 bags per cubic yard by volume (since 27 cu ft ÷ 0.75 = 36). The weight-based calculation gives 50 bags; the volume-based gives 36 bags — the difference reflects moisture content variation. Our calculator uses volume-based math since bags are labeled in cubic feet, not pounds.

How much does topsoil weigh per cubic yard?+

Dry screened topsoil weighs approximately 2,000 lbs (1 ton) per cubic yard. Wet topsoil can weigh up to 2,400 lbs per yard. Fill dirt is slightly heavier at about 2,200 lbs per yard. Compost-rich garden mix is lighter at 1,400–1,600 lbs per yard. For truck payload calculations, always use the higher wet estimate to be conservative — topsoil delivered in rainy weather or stored outside can be significantly heavier than the dry weight.

How deep should topsoil be for a vegetable garden?+

The minimum for most vegetables is 6 inches of quality topsoil or garden mix. Deep-rooted vegetables like tomatoes, peppers, carrots, and squash perform best with 12+ inches of well-drained, nutrient-rich soil. For in-ground beds, till existing soil to 8–10 inches and add 4–6 inches of amended topsoil on top to achieve 12–14 inches of quality rooting depth. For raised beds, fill to the brim — 12 inches of garden mix is the widely recommended depth for almost all vegetables.

What is the 70/30 rule for raised garden bed soil?+

The 70/30 rule recommends filling raised beds with 70% quality topsoil or garden mix and 30% compost. The topsoil provides structural stability, water retention, and mineral content. The compost adds nutrients, improves drainage, and supports the microbial life that feeds plants. A variation is the 60/30/10 mix: 60% topsoil, 30% compost, 10% perlite or coarse sand for superior aeration. Never use 100% topsoil in a raised bed — it compacts heavily with repeated watering.

Is it cheaper to buy topsoil in bulk or bags?+

Bulk is almost always dramatically cheaper. Bagged topsoil (40 lb bag at $5.98) works out to approximately $240–$360 per cubic yard when purchased at retail. Bulk screened topsoil delivered runs $35–$80 per cubic yard depending on region and quality — roughly 3–7× cheaper. The only situations where bags make sense are very small projects (under 0.5 yd³), when you cannot receive a delivery truck, or when you need a specific product not available in bulk (like a pre-blended raised bed mix). For anything over 1 yard, call a local landscape supply yard.

How much does topsoil cost per yard in the US?+

Bulk topsoil pricing in the US ranges from $15–$80 per cubic yard depending on quality and region. Screened topsoil typically costs $35–$65/yd³ delivered. Premium garden mix or amended soil runs $55–$90/yd³. Fill dirt is the cheapest at $15–$35/yd³. Delivery fees add $50–$150 for most residential loads up to 10–15 yards. Urban areas on the coasts (LA, NYC, Boston) tend to run 30–50% higher than Midwest and Southern markets. Always get 2–3 quotes — pricing varies significantly between suppliers even in the same zip code.

How do I calculate topsoil for a raised bed?+

For raised beds you fill the entire box, not just a surface layer. Volume = Length × Width × Depth (all in feet). Convert depth from inches to feet by dividing by 12. Divide by 27 for cubic yards. Example: a 4 × 8 × 12 inch bed = 4 × 8 × 1 = 32 cu ft ÷ 27 = 1.19 yd³. Add 20% for settling: 1.43 yd³. For the 70/30 mix: 1.0 yd³ of topsoil + 0.43 yd³ of compost. Our raised bed preset handles all this automatically and shows you the 70/30 breakdown.

How much topsoil do I need to topdress a lawn?+

For topdressing, apply ¼ to ½ inch max per session to avoid smothering grass. At ½ inch, 1 cubic yard covers 648 sq ft. At ¼ inch, 1 cubic yard covers 1,296 sq ft. For a 5,000 sq ft lawn at ½ inch: 5,000 ÷ 648 = 7.7 yards. Add 10% settling: 8.5 yards. Most homeowners overestimate how much topdressing they need — less than ½ inch applied evenly is more effective than a thick, uneven layer that mats the grass.

Can I put topsoil over an existing lawn?+

Yes — this is topdressing, and it is standard lawn maintenance practice. Apply no more than ½ inch in a single application. Use a screened topsoil or compost mix for best results. Aerate the lawn first with a core aerator to create channels for the soil to settle into. Rake the topsoil evenly across the surface, then overseed if desired. Water well after application. Applying more than ½ inch at once will smother the existing turf — the grass blades need light to continue photosynthesizing. Multiple thin applications spaced 2–4 weeks apart are better than one thick application.

What is the difference between topsoil and fill dirt?+

Topsoil is the fertile, organic-rich top layer of soil — typically the first 2–8 inches of the ground. It contains organic matter, beneficial soil organisms, and the nutrients that support plant growth. Fill dirt is subsoil — it comes from below the topsoil layer, is mostly mineral material with very little organic content, and compacts well. Use topsoil for lawns, gardens, and raised beds. Use fill dirt for structural applications (grading, filling behind retaining walls, building up grade) and then cap with topsoil for any areas where you want to grow plants.

How many cubic yards fit in a pickup truck?+

For topsoil (approximately 2,000 lbs/yd³): A half-ton pickup (1,000 lb safe payload) can carry about 0.5 cubic yards safely. A 3/4-ton truck (1,500 lb payload) can handle about 0.75 yards. A 1-ton truck (2,000 lb payload) can carry about 1 full yard. Never exceed your truck’s payload rating — topsoil is heavy and blows out shocks, tires, and transmissions far faster than most homeowners expect. For projects over 1 yard, schedule delivery.

What is screened topsoil?+

Screened topsoil has been processed through a rotary or vibrating screen to remove rocks, roots, debris, and large clumps, leaving a uniform, fine-textured soil. It is the premium product used for lawns, garden beds, and finished grading. Unscreened topsoil is the raw excavated material before processing — it is cheaper but may contain rocks and debris that interfere with seeding and planting. For any application where you will be seeding grass or planting, screened topsoil is worth the extra cost per yard.

How long does topsoil take to settle?+

Loose topsoil placed in a new lawn or garden bed settles 10–20% over the first 3–6 months of watering and weather exposure. Most of the settling happens in the first few rain events after placement. This is why our calculator adds a default 15% settling allowance — order more than your calculated raw volume so that after settling, you still end up at your target depth. For raised beds, plan for 20–25% settling since the loose soil has nowhere to compact into and will consolidate significantly after the first season.

How many bags of topsoil do I need for a 4×8 raised bed?+

A 4 × 8 × 12 inch raised bed requires 32 cubic feet = 1.19 cubic yards of soil (before settling). With 20% settling allowance: 1.43 yards = 38.6 cubic feet. At 1.5 cu ft per bag: 26 bags. At 1 cu ft per bag: 39 bags. At 40 lb bags (≈0.75 cu ft each): 52 bags. For the 70/30 mix on a single 4×8 bed: buy about 26 bags of topsoil/garden mix and 11 bags of compost (at 1 cu ft each). Or: order 1 yard of garden mix + 0.5 yard of compost in bulk for much better value.

What is the best topsoil for lawn establishment?+

For new lawn installation, look for screened topsoil with a pH of 6.0–7.0, organic matter content of 4–8%, and good drainage. Ask your supplier if the topsoil is from agricultural land or former woodlands — both tend to be higher quality than topsoil stripped from construction sites. Avoid topsoil that looks very dark and swampy (may be high in clay) or very pale and sandy (will dry out fast). If you can request a basic soil test from the supplier, do so — it prevents expensive soil amendment work after the lawn fails in year one.

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Legal Disclaimer & Editorial Transparency

The Topsoil Calculator on USCalculators.com is provided free of charge for planning and estimation purposes only. Volume, weight, bag count, and cost figures are mathematical estimates based on the dimensions and prices you enter. Actual material requirements will vary based on soil settling rates, existing ground conditions, irregular bed geometry, and soil density variation by supplier and moisture content.

Topsoil density values used in this calculator (ranging from 1,200–2,200 lbs per cubic yard depending on soil type) represent industry-standard averages. Actual supplier material density may differ — particularly for compost-rich mixes which can vary significantly. The 70/30 raised bed mix recipe is a widely accepted gardening guideline, not a prescriptive formula; individual plants and growing conditions may benefit from different ratios. Always confirm volume, weight, and pricing with your local landscape supplier before placing an order.

Truck payload guidance reflects general manufacturer payload ratings. Always consult your specific vehicle’s door-jam sticker and owner’s manual for your rated payload. Topsoil is heavy — never exceed rated payload. Depth recommendations reference guidelines from the University of Minnesota Extension and other land-grant university extension services; these are general guidelines and your specific site conditions may differ. USCalculators.com is not affiliated with any soil supplier, hardware retailer, or government agency.