Topsoil Calculator for Lawns, Garden Beds and Raised Beds

How to use the topsoil calculator

1. Choose what you are filling. Lawn / garden area covers ground-level areas: a new lawn, a regraded patch or an in-ground garden bed. Raised beds takes the inside length, width and soil depth of each bed and how many of that size you have.
2. Add every area. Use rectangles and circles, or type a known square footage. Odd shapes can be split into pieces.
3. Pick a depth. Penn State Extension says new turf typically needs at least 4–6 in of firmed or settled topsoil. University of Illinois and University of Missouri Extension say raised beds should be at least 6–12 in deep.
4. Add settling if needed. Bagged and bulk soil is loose and settles after it is spread, watered and walked on. If your target depth is a settled depth, add a percentage to cover it.
5. Check the weight. Some yards sell soil by the ton. The default of about 1.03 tons per cubic yard is for loose dry topsoil. Packed or wet soil weighs more, so use your supplier’s number if they give one.

How to calculate how much topsoil you need

A quick check: one cubic yard covers 324 sq ft at 1 in deep. Divide 324 by your depth in inches. A yard covers 81 sq ft at 4 in, 54 sq ft at 6 in and 27 sq ft at 12 in.

The weight figure comes from a published material weight chart. It lists topsoil at 2,050 lb per cubic yard loose, 2,565 lb packed and 3,375 lb wet. That spread is why “tons” is the least reliable unit for soil. Order by the yard when you can.

Worked examples

A 20 × 10 ft area, 4 in deep

200 sq ft × 4 ÷ 12 = 66.7 cu ft = 2.47 cubic yards, about 2.5 tons loose. In bags: 89 of 0.75 cu ft, 67 of 1 cu ft, 45 of 1.5 cu ft or 34 of 2 cu ft. At this size bulk delivery usually makes more sense than carrying 45 bags.

Topsoil for a new lawn

A 1,000 sq ft lawn at 6 in deep, the top of Penn State’s 4–6 in range, needs 500 cu ft = 18.5 cubic yards, roughly 19 tons loose. At 4 in it needs 12.3 cubic yards. Penn State also suggests working about 2 in of the new topsoil into the top 2–3 in of the subsoil, so the two layers don’t form a barrier for roots and water.

One 4 × 8 ft raised bed, 12 in deep

4 × 8 × 1 = 32 cu ft = 1.19 cubic yards. That is 22 bags of 1.5 cu ft or 16 bags of 2 cu ft. Using the Illinois Extension example mix (40% topsoil, 40% compost, 20% soilless mix), you would buy 12.8 cu ft of topsoil, 12.8 cu ft of compost and 6.4 cu ft of soilless mix.

Three raised beds

Three 4 × 8 ft beds at 12 in hold 96 cu ft, or 3.56 cubic yards. That is 64 bags of 1.5 cu ft, a strong case for a bulk load of blended garden soil.

Raised bed soil and garden soil

Raised beds are easy to fill with the wrong thing. Extension guidance is fairly consistent:

• Depth: at least 6–12 in for good root growth. The University of Missouri adds that deeper is better and that some rooting depth can come from loosened soil under the bed. Beds taller than 18–24 in need real retaining walls.
• Width: no more than 4 ft if you can reach from both sides, 3 ft from one side (Illinois Extension). You should never need to step into the bed and compact it.
• Mix: good topsoil plus plenty of organic matter. The 40/40/20 topsoil, compost and soilless-mix split is one example. Peat moss, compost and well-rotted manure are other common sources of organic matter.
• Don’t layer. Mix new soil into the soil below instead of leaving distinct layers. Layers slow water movement and root growth.

For in-ground garden beds, the calculator works the same way: enter the bed area and the depth of soil you are adding. Measure the depth you add, not the total depth of the bed.

Buying tips

• Bags vs bulk. One cubic yard is 18 bags of 1.5 cu ft or 13.5 bags of 2 cu ft. Above a couple of yards, bulk is usually cheaper and much less work.
• Ask what you are buying. “Topsoil”, “garden soil” and “raised bed mix” are not standard grades. Ask the yard what is in it, and whether they have a soil test.
• Plan the drop spot. A dump truck needs a clear, firm place to unload. Put a tarp down if it lands on a driveway or lawn.
• Finish with mulch. Once beds are planted, use the mulch calculator for the top layer. For gravel paths between beds, use the gravel calculator. If you are building a patio next to the garden, try the paver calculator. Seeding a lawn on the new soil? The grass seed calculator gives pounds of seed by grass type.

Sources & assumptions

How this calculator gets its numbers. Full method: our methodology.

• Volume = area × depth (or length × width × depth for each raised bed); 27 cu ft = 1 cubic yard. Bags are 0.75, 1, 1.5 or 2 cu ft and are rounded up.
• Weight uses 2,050 lb per cubic yard for loose topsoil (about 1.03 short tons). Wet or packed soil is heavier (2,565–3,375 lb in the same chart), so ask your supplier how they weigh it.
• The settling allowance defaults to 0%. Penn State's 4–6 in lawn figure is a firmed or settled depth, so add some if you are filling to a settled depth.
• The raised-bed mix of 40% topsoil, 40% compost and 20% soilless mix is one example from University of Illinois Extension, not the only good recipe.

Sources

1. Penn State Extension, Lawn Establishment. Typically a minimum of 4 to 6 in (firmed or settled depth) of good-quality topsoil is needed to establish turf.
2. University of Illinois Extension, Raised Bed Checklist. Beds at least 6–12 in deep, no more than 4 ft wide if reachable from both sides; example mix 40% topsoil, 40% compost, 20% soilless mix.
3. University of Missouri Extension, Raised-Bed Gardening (G6985). Most plants need at least a 6–12 in rooting zone; beds higher than 18–24 in need retaining walls.
4. Two Rivers-Ottauquechee Regional Commission (Vermont), Material Weight: Pounds per Cubic Yard. Topsoil 2,050 lb/yd³ loose, 2,565 packed, 3,375 wet.

Last reviewed October 25, 2026. Product figures vary by brand; the label on what you buy wins.