Topsoil Calculator

How to use this topsoil calculator

1. Pick the job first. Depth is the number people guess at, and it is the number that moves the answer most. Choosing "sod bed prep" or "lawn topdressing" sets a depth a contractor would actually use, and you can still type over it.
2. Measure the area in feet. Rectangle, circle, triangle or a border ring. An irregular yard is not one clever average, it is two or three rectangles added together, so use "Add another area" rather than eyeballing a mean.
3. Set the soil type. This only changes the weight, not the volume, but the weight is what decides whether your truck can carry it and how many 40 pound bags a yard works out to.
4. Read the order figure, not the raw one. Suppliers sell in half yards with a one yard minimum, so the tool shows you what to actually ask for as well as what you strictly need.
5. Check the haul panel before you drive over. If it says the load is over your payload, believe it. Take the order sheet PDF with you so you are not doing arithmetic at the scale house.

Why this topsoil calculator is different

Most topsoil calculators are the same box: length, width, depth, one number out. They are not wrong, they just stop before the questions that actually come up when you are standing in a yard with a tape measure.

• It runs backwards. Half of what people ask about topsoil is the other direction: I have three yards coming, how far does that go? Nothing else on the first page of results will answer that. Switch to "What will it cover?" and you get the square footage, plus the same load at every other depth.
• It picks the depth for you. Every other calculator makes you supply the one input you are least sure about. Eight job presets set a depth a contractor would use, with the reason attached.
• It tells you what the load weighs, and whether your truck can take it. Bulk topsoil is weight limited long before it is volume limited. A single cubic yard of moist soil is over a ton, which is more than a half ton pickup is rated to carry, and the yard hand filling your bed is not the one who has to stop it.
• It handles more than one area. A real project is a lawn at two inches plus beds at six, and adding those up by hand is where the arithmetic errors live.
• It knows a bag is not always a volume. A 1.5 cubic foot bag is a volume, so 18 of them make a yard whatever the soil. A 40 pound bag is a weight, so it takes about 50 of them when the soil is dry and closer to 56 when it is not. Calculators that hardcode one number are wrong half the time.
• Free to embed, no cart attached. Most of the pages ranking for this search are there to sell you the soil. This one is not selling soil, and you can put it on your own site.

How it works (the math)

It is geometry and unit conversion. Nothing here is proprietary:

Area (sq ft)   rectangle  A = L x W
               circle     A = pi x (d/2)^2
               triangle   A = (b x h) / 2
               ring       A = pi x (Ro^2 - Ri^2)

Volume         cubic feet  = A x depth_in / 12
               cubic yards = cubic feet / 27  =  A x depth_in / 324

Weight         pounds = cubic yards x density
               tons   = pounds / 2000

Bags           volume bag  n = ceil(cubic feet / bag cu ft)
               weight bag  n = ceil(pounds / bag lb)

Coverage       sq ft = cubic yards x 324 / depth_in

Where 324 comes from. A cubic yard is 27 cubic feet, and there are 12 inches in a foot, so one cubic yard spread one inch deep covers 27 x 12 = 324 square feet. That makes square feet x inches / 324 an exact shortcut to cubic yards, not an approximation, and it is the number worth memorising: one yard covers 324 square feet at an inch, 162 at two inches, 108 at three.

Where the weight comes from. Soil is quoted by volume and hauled by weight, so the two have to be bridged by density. The presets are derived from soil bulk density in grams per cubic centimetre at 1 g/cm³ = 62.42796 lb/ft³, multiplied by 27. USDA-NRCS puts an ideal silt loam at 1.33 g/cm³, which is where the screened topsoil default of about 2,240 pounds a yard comes from.

Every fixture in sites/diy/src/data/tools/topsoil-calculator/fixtures.json runs in CI before each deploy, including the figures quoted on this page. If the math and the words ever disagree, the build fails rather than the page going out wrong.

How deep should topsoil go?

This is the input that decides your order, and it is the one nobody tells you. The short version: over living grass you are limited to a quarter inch at a time, and over bare ground you are limited only by budget.

The quarter inch limit on topdressing is the one people ignore, and it is the one that kills lawns. Grass buried under an inch of soil in one pass does not push through it. If you have real dips to fill, do a quarter inch now and another in a month, or strip the sod, fill properly, and lay it back. Mow short before you spread, either way, so the soil reaches the ground instead of sitting on the leaf blades. Our lawn mower guide covers which machines cut low cleanly without scalping the high spots.

What a cubic yard of topsoil covers

Working from the other end, because this is how bulk soil is actually sold. One cubic yard, at each common depth:

A ton is a slightly different question, because a ton is a weight and coverage is a volume. At the screened topsoil default of about 2,240 pounds a yard, one ton is a little under nine tenths of a cubic yard, so it covers roughly 145 square feet at two inches deep. Dry soil is lighter, so a ton of it goes further, around 160 square feet at the same depth. That is the whole reason the soil type picker exists.

Three worked examples

Prepping 1,000 square feet for sod

A 20 by 50 foot patch with two inches of screened topsoil under it comes to 6.17 cubic yards, so you order 6.5 and have a little spare for the low corner you will find once it is raked. That load weighs about 6.9 tons, which is a delivery, not a pickup. In bags it would be 112 at 1.5 cubic feet each, which is why nobody bags a job this size.

Topdressing the same lawn

The same 1,000 square feet at a quarter inch is 0.77 cubic yards. You will still pay for a full yard because that is the delivery minimum, and you will still have soil left over, which is fine because topdressing is a repeat job. This is the case where bags genuinely compete: 11 bags at two cubic feet does it, and they fit in the car.

A mixed project, which is what most of them are

Say 500 square feet of lawn at two inches, three raised beds four by eight at twelve inches, and a 100 square foot flower bed at four. Added up that is 7.88 cubic yards, so eight on the order. Done one area at a time on a calculator that only takes one shape, this is exactly where a yard goes missing. Note that for the contained beds you are usually better off with a proper mix than straight topsoil, which the raised bed soil calculator works out by recipe.

What affects how accurate this is

• Your depth, more than anything. Doubling the depth doubles the order. An inch of error over 1,000 square feet is three cubic yards, which is most of a delivery.
• Settling. Bulk soil arrives loose and compacts 10 to 20 percent once it is spread, walked on and watered. The settling toggle adds 15 percent, which is the middle of that range. Leave it on for anything you need to finish flush.
• Moisture, for the weight only. The volume you need does not change when it rains, but the weight does, by a third between dry and soaked. Weight is what your truck and your back care about.
• What the yard actually loads. A "yard" from a loader bucket is an estimate by eye. Some suppliers run generous, some do not. Order to the half yard and keep the receipt.
• Screened against unscreened. Unscreened soil carries rock and root that you will rake out and cart away, so the usable volume is less than what you paid for. For anything you are seeding, buy screened.
• Irregular ground. Depth over a dished lawn is deeper in the middle than at the edges. If you are filling a real hollow rather than skimming a flat area, measure the hollow as its own area.

Frequently asked questions

How do I calculate how much topsoil I need?

Multiply the length by the width in feet to get square feet, multiply that by the depth in inches, then divide by 324. That gives you cubic yards, which is how bulk topsoil is sold. For example, 20 by 50 feet at two inches deep is 1,000 x 2 / 324 = 6.17 cubic yards. Round up to the half yard, because that is the increment suppliers deliver in and because soil settles once you spread it.

How many 40 pound bags of topsoil equal 1 cubic yard?

Between about 50 and 56, and which end you land on depends on how wet the soil is. A 40 pound bag is sold by weight, not volume, so the drier the soil the more volume you get per bag. At the dry end, around 2,020 pounds a cubic yard, it takes about 50 bags. At typical screened topsoil weight, around 2,240 pounds, it is closer to 56. Bags sold by volume are simpler: 18 bags at 1.5 cubic feet, or 27 at one cubic foot, make a yard every time.

How much will 3 yards of topsoil cover?

486 square feet at two inches deep, 972 at one inch, and 324 at three inches. Three cubic yards is 81 cubic feet, and the depth is what decides how far it stretches. Switch this calculator to "What will it cover?" and it gives you the figure at your depth plus the same load at every other common depth.

How much will 1 ton of topsoil cover?

About 145 square feet at two inches, if it is typical screened topsoil at roughly 2,240 pounds a cubic yard. That works out to just under nine tenths of a yard. Dry soil weighs less per yard, so a ton of it is more material and covers closer to 160 square feet at the same depth. If a supplier quotes you in tons rather than yards, ask which they are weighing, because a wet ton is noticeably less soil than a dry one.

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

Bulk wins past roughly 15 to 20 bags, and it is not close once you get to a full yard. The catch is the delivery minimum: most suppliers will not bring less than a yard and will charge a delivery fee on top, so under about half a yard bags are usually cheaper and they fit in a car. The calculator flags both cases, telling you when your bag count has crossed into bulk territory and when your bulk order is under the minimum you will be charged for.

Related tools

• Sod Calculator for the square footage and roll count once the bed is prepped
• Raised Bed Soil Calculator for contained beds, where you want a soil mix by recipe rather than straight topsoil
• Retaining Wall Calculator for when the low spot needs holding back rather than filling
• Browse all free tools by Jake →

What you need to spread it

Ordering the soil is the easy part. Moving and levelling it is where the day goes:

• Best Lawn Mowers for cutting short before you topdress, so the soil falls to the ground rather than sitting in the canopy.
• Best Garden Hoses because new soil wants a deep soak the day it goes down, and the reach of the hose decides whether that actually happens.
• Best String Trimmers for the edges and borders the mower cannot reach before you start spreading.
• Best Cordless Leaf Blowers for the driveway after a bulk load gets dumped on it, which beats sweeping and beats staining the concrete.
• Essential Tools for New Homeowners if the barrow and the landscape rake are not in the garage yet.

Sources & methodology

• Soil bulk density for the weight presets, converted from g/cm³ at 62.42796 lb/ft³ and multiplied by 27. Silt loam at 1.33 g/cm³ is the screened topsoil default. (USDA-NRCS, Soil Health: Bulk Density/Moisture/Aeration, Guides for Educators, May 2019, Table 1 and p.2)
• Bulk density fundamentals and the ranges for compacted against well-aggregated soil. (USDA-NRCS, Soil Quality Indicators: Bulk Density)
• Volume conversion: 1 cubic yard = 27 cubic feet, so a cubic yard covers 324 square feet one inch deep. 324 = 27 x 12 exactly, which makes the shortcut exact rather than approximate.
• Cross-validation: the cubic yard figures, the 324 shortcut and the multi-area worked example were checked against the calculators and guides currently ranking on page one for this search, and agree to the decimals they display.

The geometry and unit conversions here are fixed, so this tool does not go stale. Density presets are reviewed if NRCS republishes its bulk density table. About Jake · Last reviewed August 21, 2026.

Embed this tool on your site

Free for landscapers, soil and aggregate suppliers, garden centres, extension offices, /r/landscaping, /r/lawncare and /r/gardening. Required attribution is in the snippet. No fee, no account, no analytics attached to the embed.

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  Topsoil calculator by
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  &middot; Reviewed by Jake Morrison, Licensed GC
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