Topsoil Calculator: How Much Soil Do You Really Need? (Yards, Tons & m³)

Ordering soil by guesswork usually ends one of two ways: a mountain of dirt blocking the driveway, or a half-filled bed and a second delivery fee. The calculator above takes the guessing out of it. Enter the size of your lawn, garden bed or raised bed, pick a depth, and it gives you the amount in cubic yards, cubic feet, cubic metres, tons, tonnes, trailer loads and bags.

Whether you call it a topsoil calculator, a top soil calculator, a garden soil calculator or simply a soil calculator, the job is the same: turn your measurements into a number a supplier can actually deliver. This one works in feet and inches for US readers and in metres and centimetres for UK readers, and you can switch between the two at any time.

If you would rather see the maths, check a supplier’s quote, or just want a quick chart, the rest of this guide covers the formulas, depth recommendations, coverage tables and worked examples.

How to use this soil calculator, step by step

Think of it as the “how much soil do I need” calculator you were searching for: measure, enter, read the result. It takes about a minute.

1. Choose your units. Pick Imperial (feet and inches) or Metric (metres and centimetres). You can still change the unit on any single field, so a bed measured in feet with a depth in centimetres works fine.
2. Start with a quick start or a shape. Raised bed, garden bed, new lawn and crops/orchard fill in sensible sizes for you. Otherwise pick rectangle, circle, or “I know the area”.
3. Enter your measurements. For a rectangle, use length and width. For a round bed or tree pit, use the diameter. If you already know the total area, choose “I know the area” and enter it in square feet, square yards or square metres. That makes it a quick topsoil calculator in square feet as well.
4. Set the depth. Use the depth guide further down if you are unsure.
5. Enter how many identical beds or holes you have. Building three raised beds of the same size? Enter 3 and the tool multiplies for you. Keep it at 1 for a single bed. Do not use it for the number of plants in a bed, because that does not change the soil volume.
6. Choose extra for settling and the soil type. 10% extra is the recommended default. The soil type only changes the weight figures, not the volume.
7. Read the results. You get a headline amount, then volume, weight and an ordering guide with trailer loads and bag counts.

Measuring tip: for raised beds, measure the inside of the frame, not the outside. For an irregular shape, split it into rectangles and circles, run each one through the calculator, and add the totals.

Topsoil calculator yards, tons or tonnes: which number should you use?

Suppliers do not all sell soil the same way, which is why the calculator shows several units at once. People who search for a “top soil calculator yards” tool usually want cubic yards, which is what US soil yards sell by. Whatever you type into Google, use the unit that matches how you are buying.

How to calculate how much soil you need (the formulas)

Whether you search for a cubic yard calculator soil tool or a soil yard calculator, they all run the same three steps: work out the area, multiply by depth, then convert to the unit you need. Here they are so you can check any result by hand.

Imperial (feet, inches, cubic yards)

Cubic feet = length (ft) × width (ft) × depth (ft)

Depth in feet = depth in inches ÷ 12

Cubic yards = cubic feet ÷ 27

Metric (metres, centimetres, cubic metres)

Cubic metres = length (m) × width (m) × depth (m)

Depth in metres = centimetres ÷ 100, or millimetres ÷ 1,000

Litres = cubic metres × 1,000

Circles and weight

Area of a circle = 3.1416 × (diameter ÷ 2) × (diameter ÷ 2)

Weight = volume × soil density (see the weight table below)

Example: a garden bed measuring 10 ft × 4 ft, filled to 6 in deep. The area is 40 sq ft, and 6 in is 0.5 ft, so the volume is 20 cubic feet. Divide by 27 and you get 0.74 cubic yards. Add 10% for settling and you order about 0.81 cubic yards.

Topsoil calculator square feet chart: how far does a cubic yard go?

If you already know your area in square feet, you can skip the length and width. One cubic yard is 27 cubic feet, so it covers 324 square feet at 1 inch deep. For any other depth, divide 324 by the depth in inches. The table below does that for you, with the amount needed for common areas. Figures are before adding extra for settling.

Metric coverage chart

In metric it is even simpler: one cubic metre covers 1 ÷ depth (in metres) square metres. So at 100 mm deep (0.1 m), one cubic metre covers 10 m².

How deep should topsoil be?

Depth is the number people most often get wrong, and it has the biggest effect on the total. Use these ranges as a starting point and adjust for how good your existing soil is.

Before adding a thick layer of new soil, loosen the compacted surface underneath. A hard, smooth base can stop water draining and roots going down.

Raised bed soil calculator: how much soil for a raised garden bed

A raised bed is really just a box to fill, so the maths is simple. Use the inside length and width, and set the depth to how high you will fill it. The calculator works as a raised garden bed soil calculator straight away: hit the Raised bed quick start, change the size to match your frame, and you have your number. If you need a soil calculator for raised bed builds of several sizes, enter the number of beds and it multiplies for you.

Soil calculator raised bed chart: common sizes (imperial)

Soil calculator raised bed chart: common sizes (metric)

What to fill a raised bed with

Do not fill a raised bed with topsoil alone. It packs down and drains slowly. One widely used blend is about 60% topsoil, 30% compost and 10% coarse sand or perlite for drainage. Some gardeners prefer roughly half topsoil and half compost. Either way, work out the total volume first, then split it. Here is the 60/30/10 split for a 4 × 8 ft bed filled 12 in deep, including 10% extra:

For weight, choose “Raised bed mix” under soil type in the calculator. A soil and compost blend is lighter than plain topsoil.

Tip: you can save soil by filling the bottom of a deep bed with logs, branches or rough plant material and topping it with your mix. Just keep the top 8 to 12 in as proper growing soil. You will find more home-growing ideas in our gardening tips section.

Garden bed soil calculator: flower beds and vegetable plots

For an in-ground bed, use the same length × width × depth approach, but remember what is already there. If your bed has 4 in of decent soil and you want 10 in in total, you only need to buy 6 in of new soil. Measure the gap, not the finished depth. And if you are still deciding how big the plot should be, the vegetable garden size calculator helps you plan the space before you order any soil.

If you are working out a garden soil calculator figure for several beds of the same size, use the number of beds field. For beds of different sizes, run them one at a time and add the results together before you order.

Cubic yards, cubic feet, cubic metres, tons and tonnes explained

Volume conversions

How much does topsoil weigh?

Weight depends on the type of soil and how wet it is, so treat these as typical values rather than exact ones. US suppliers commonly quote around 1.1 to 1.2 tons per cubic yard for screened topsoil, while UK suppliers often quote 1.3 to 1.5 tonnes per cubic metre. Wet or compacted soil can be a good deal heavier. If you are curious how much water a soil can hold, try the soil water holding capacity calculator.

A US ton (short ton) is 2,000 lb. A metric tonne is 1,000 kg, which is about 2,205 lb, so one tonne is roughly 1.1 US tons. If a price is quoted per ton or per tonne, check which one it is.

If you are comparing quotes, ask your supplier what moisture their weight figure assumes. Ordering by volume (cubic yards or cubic metres) is often the fairest way to compare, and it is how most US soil yards price it.

Trailer loads and bulk bags (a UK-style ordering guide)

In the UK, and on many farms and smallholdings elsewhere, soil is often sold by the trailer load. A commonly used rule of thumb for a standard 6 × 4 ft trailer is that one load is about 0.7 cubic metres. Suppliers tend to round loads up, which is why 1½ loads are usually treated as one cubic metre.

These are approximations. Trailer sizes, how high they are heaped and the moisture in the soil all change the real figure. The calculator uses 0.7 m³ per load and shows a rounded-up order to the nearest half load.

How many bags of soil do you need?

Remember that 1 cubic metre is 1,000 litres. To work out bags, divide your total volume in litres (or cubic feet) by the size of the bag and round up. The table shows how many bags make up a cubic yard or a cubic metre.

“Bulk bag” is not a fixed size. Bags sold under that name can hold anything from about 500 L to over 1,000 L, so compare litres, not bag counts. Always check the volume printed on the actual bag.

As a general rule, bags suit small jobs and top-ups. Once you pass roughly half a cubic yard (or half a cubic metre), delivered bulk soil is usually cheaper per unit, and for larger jobs a loose load is often the cheapest way of all.

How much extra topsoil should you order?

Soil settles once it is watered and walked on, and some is always lost in spreading. A small surplus is easy to use up. A shortfall means another delivery charge. That is why the calculator adds 10% by default.

Worked examples from the calculator

Here are five typical jobs, using the calculator’s default settings (10% extra unless stated, and standard screened topsoil for weight unless stated).

Topsoil vs garden soil vs compost vs fill dirt

Getting the quantity right is only half the job. Buying the right material matters just as much, and the names are used loosely by suppliers.

In the UK, look for topsoil sold to BS 3882, the British standard for topsoil, which grades it by quality. Whatever you buy, ask whether it is screened.

For orchards, allotments and larger plots

The Crops / orchard quick start is set up for tree planting pits, which is why it uses a circle and a number of holes. For big beds or whole plots, choose “I know the area” and enter the total. If your land is measured in acres, hectares, kanal or marla, the agriculture area calculator converts it to square feet or square metres first. Two useful reference points: 1 acre is 43,560 sq ft, so a 1 in layer over an acre is about 134 cubic yards. One hectare is 10,000 m², so a 10 mm layer over a hectare is 100 m³.

For large areas, it is worth having your soil tested first. A test tells you whether you need topsoil at all, or whether compost, lime or another amendment would do more for the money.

Common mistakes when working out how much soil you need

• Mixing up units. Feet and inches are the classic trap. A depth of 6 must be entered as 6 in, not 6 ft.
• Confusing cubic yards with square yards. A cubic yard measures volume. A square yard measures area. Soil is sold in cubic yards.
• Measuring the outside of a raised bed. The frame takes up space. Measure inside.
• Forgetting the soil that is already there. Only buy the gap between what you have and the depth you want.
• Ordering the exact amount. Settling and spillage are real. Add 5% to 15%.
• Ignoring weight. If you are billed by the ton or tonne, wet soil costs more for the same volume.
• Comparing bag counts instead of litres. Bags of the same name can differ a lot in size.
• Skipping the delivery check. Make sure a truck can reach your site, and have a tarp or a clear spot ready for the pile.

Topsoil calculator FAQs

Final thoughts

Measure carefully, choose a sensible depth, add a little extra, and check how your supplier sells the soil. Do those four things and you will order the right amount the first time. croll back up and run your numbers through the calculator whenever you plan a new lawn, garden bed, raised bed or planting job, and browse our other farm calculators for the rest of your growing plans.