Topsoil Calculator

How to calculate how much topsoil you need

Topsoil is sold by the cubic yard in bulk, by the ton at some yards, and by the cubic foot in bags. Start with volume:

Cubic yards = area (ft²) × depth (in) ÷ 324

Then multiply by about 1.1 to get US tons, or multiply cubic yards by 27 and divide by the bag size for bags.

1. Measure the area in feet. For irregular lawns, split into rectangles, run each one and add the results.
2. Decide the finished depth you want to add, not the depth of the hole.
3. Run the formula or the calculator. It shows cubic yards, cubic feet, cubic meters and tons.
4. Add 10–20%. Loose topsoil settles after rain and rolling, so order a little more than the measured volume.

Topsoil for common areas

This table covers the sizes people search for most, at 4 in (new lawn) and 6 in (deeper beds and regrading). Tons use the calculator’s assumed 1.1 tons per cubic yard; your supplier’s figure may differ.

Tons and “with 10% extra” match because the density, 1.1 tons per yard, happens to equal 1 plus 10%. For metric areas, each centimetre of depth needs 10 litres (0.01 m³) per square metre, so 10 cm over 50 m² is 5 m³.

How much topsoil per square foot?

Each square foot needs depth (in) ÷ 12 cubic feet of topsoil. At 4 in that is 0.333 ft³ per square foot; at 1 in it is 0.083 ft³. Per 100 ft², the figures below are easy to scale to any lawn or bed.

For a 600 ft² area (20 × 30 ft) at 4 in, multiply the 4 in row by six: 7.41 yd³, about 8.15 tons. For a 30 × 30 ft area (900 ft²) at 4 in it is 11.11 yd³.

Topsoil for 1,000, 1,500 and 2,000 sq ft lawns

Lawn jobs fall into two groups: thin top-dressing over existing grass and a full layer for new seed or sod. The yardage between them differs by a factor of eight or more, so pick the job before you pick the number.

Volumes are before the 10–20% settling allowance; tons use the assumed 1.1 tons per cubic yard. A 5,000 ft² yard at 4 in is over 60 yd³, which is several truckloads, so ask suppliers how much one delivery carries and whether a larger truck can reach your drop spot.

Topsoil for leveling a yard and filling low spots

Low spots are rarely a uniform depth. Most dips run from nothing at the edge to their deepest point in the middle, so use the average depth, not the maximum. For a dip that slopes evenly from 0 to 4 in, the average is about 2 in.

1. Stretch a string line or lay a long straight board across the dip and measure the gap at several points.
2. Average the readings, including the zeros at the edges.
3. Measure the dip as a rectangle (length × width) and enter the average depth.
4. Fill in lifts of 1–2 in on existing grass so it can grow through, and water between lifts.

Deep holes and major grade changes are a different job. Fill the bulk with fill dirt, compact it in layers, and finish with topsoil on top. On 1,000 ft², 4 in of fill plus 4 in of topsoil is 12.35 yd³ of each, 24.69 yd³ in all. If water drains toward a foundation or a neighbour’s lot, get advice before regrading; drainage rules vary, so check with your local building department.

Topsoil for a garden bed

In-ground vegetable and flower beds take more soil per square foot than lawns, because roots need a deeper loose layer. For a 10 × 20 ft bed (200 ft²):

• 6 in deep: 3.70 yd³, or 4.07 yd³ with 10% extra (about 4.07 tons at the assumed 1.1 tons per yard).
• 8 in deep: 4.94 yd³, or 5.43 yd³ with extra.
• 12 in deep: 7.41 yd³, or 8.15 yd³ with extra.

If you are improving existing soil rather than replacing it, you may only need a few inches of topsoil or compost worked into the top layer. For framed beds above ground, the raised bed soil calculator has bed-by-bed bag counts.

Topsoil in metric: cubic metres and tonnes

One centimetre of depth over one square metre is 10 litres. So 10 cm over 50 m² is 5 m³. At our assumed density of about 1,305 kg per m³ (the metric equivalent of 1.1 US tons per cubic yard), that is about 6.53 tonnes.

Suppliers in metric countries often sell topsoil by the bulk bag rather than the cubic metre. Ask what volume the bag holds, since bulk bags come in different sizes.

How deep should topsoil be?

It depends on the job. Thin layers feed an existing lawn; deep layers build a new one.

These are common practice, not rules. Poor subsoil, heavy clay and drainage problems may call for more, and your local cooperative extension office can advise on soil for your area. For raised beds, use the raised bed soil calculator, which works in cubic feet and bag counts.

How much does a yard of topsoil weigh?

There is no single published weight; it depends on moisture, clay and stone content. Our calculator assumes 1.1 US tons (2,200 lb) per cubic yard, about 81 lb per cubic foot or 1.3 tonnes per cubic metre. Use your supplier’s figure when they give one.

Real soil varies. Wet soil, clay and screened soil with stones all weigh more, and suppliers who sell by the ton may weigh a different product than you expect. Two practical points:

• Ask for the supplier’s tons per yard and enter it if you buy by weight.
• Check your truck’s payload. A single cubic yard at 2,200 lb is heavy, so compare it with the payload on your door-jamb label before loading.

Bags or bulk topsoil?

For a raised bed or a few low spots, bags are fine. For a lawn, bulk is far less work.

• 1 yd³ = 27 bags of 1 ft³, 36 bags of 0.75 ft³ or 13.5 bags of 2 ft³.
• A 40 lb bag holds roughly 0.49 ft³ at our assumed density, so about 55 bags of 40 lb make a yard. Bag weights and volumes vary by brand and moisture, so go by the cubic feet on the label.
• Prices vary widely by region and screening quality, so we do not quote an average. Get a price per yard and a delivery charge from two or three local suppliers, then enter them in the calculator.

Topsoil for overseeding and top-dressing a lawn

Top-dressing spreads a thin layer of screened topsoil, or a soil and compost blend, over existing grass. The point is to fill small hollows and give seed contact with soil, not to bury the lawn, so depth is measured in fractions of an inch.

• ¼ in: 1 yd³ covers about 1,296 ft². A 2,000 ft² lawn takes 1.54 yd³.
• ½ in: 1 yd³ covers 648 ft². The same lawn takes 3.09 yd³.
• In bags: one 1 ft³ bag covers 24 ft² at ½ in; one 0.75 ft³ bag covers 18 ft².

Spread it with the back of a rake or a lawn leveling rake so grass blades still show through. Screened soil spreads more evenly than lumpy soil, so ask whether the supplier screens their topsoil and to what size. If you are overseeding, follow the seed label for timing and rates; this calculator sizes the soil only.

Planning a bulk topsoil delivery

A bulk load is tipped in one pile, usually where the truck can reach. A few checks before the truck arrives save hours of extra barrowing:

1. Choose the drop spot as close to the work as the truck can get, on firm ground. Ask the supplier how much room their truck needs.
2. Lay a tarp on paving or the driveway so cleanup is a matter of folding the tarp.
3. Ask how the load is measured. Some yards sell by the cubic yard loaded, others by the ton weighed; the calculator returns both so you can compare quotes.
4. Plan to spread it soon. A pile left uncovered in rain gets heavy and can wash, and a pile left on grass kills the grass under it.

As a rough guide to the work, 12.35 yd³ for a 1,000 ft² lawn is about 333 ft³ of soil to move.

Topsoil vs fill dirt

Use fill dirt (subsoil) to raise grade or fill holes, and topsoil only for the top layer where roots grow. Fill is usually cheaper and has little organic matter. Switch the calculator to Fill dirt for the lower layer and calculate each layer separately, then add the two volumes.

Our calculator uses the same 1.1 tons per cubic yard for fill dirt as for topsoil, so a 4 in fill layer on 1,000 ft² is 12.35 yd³, about 13.58 tons. Fill with rock or clay can weigh more. When you compare quotes, also ask whether the topsoil is screened (stones and roots removed) or blended with compost; those products cost and weigh differently from plain field soil, and a lower price per yard may simply be a different product.

Common mistakes when ordering topsoil

Topsoil orders go wrong in the same few ways. Each one below changes the delivery by a measurable amount.

• Ordering for the hole depth instead of the added depth. If you strip 2 in of turf and want the new surface 2 in higher than before, you need 4 in of soil, not 2. On 1,000 ft² that is 12.35 yd³ instead of 6.17 yd³.
• Forgetting settling. Loose soil shrinks after rain and rolling. For 1,000 ft² at 4 in, the measured 12.35 yd³ becomes 13.58 yd³ with 10% and 14.81 yd³ with 20%. Order the higher figure for deep fills over loose ground.
• Using the maximum depth of a dip. A dip that tapers from 0 to 4 in averages about 2 in. Using 4 in doubles the order, as the leveling example shows.
• Top-dressing too thick. Going from ½ in to 2 in on a 2,000 ft² lawn raises the order from 3.09 yd³ to 12.35 yd³, and a thick layer can smother existing grass. Thin layers, repeated, are the usual approach.
• Assuming every supplier’s ton is the same. At 1.1 tons per yard, 12.35 yd³ is about 13.58 tons; if the supplier’s damp screened soil runs closer to 1.3 tons per yard, the same volume is about 16.05 tons. Ask for their figure before you order by weight.
• Overloading a pickup. One cubic yard at our assumed 2,200 lb is already heavy for many light trucks. Check the payload on the door-jamb label first.

Topsoil calculator vs other soil and fill calculators: which one to use

This page sizes soil spread over open ground: lawns, in-ground beds, low spots and grading. Use a different tool when the job changes:

• Framed beds: the raised bed soil calculator works bed by bed in cubic feet and bag counts, including inside measurements and real board heights.
• Covering soil after planting: the mulch calculator uses the same area with mulch depths and bag sizes.
• A leveling layer of sand, for pavers or a pool base, is a sand job; the sand calculator uses sand’s heavier weight per yard.
• Converting a supplier’s tons: the tons to cubic yards converter turns a weight quote into volume and back.