Topsoil Calculator
Work out how much topsoil a job needs — volume in cubic yards and weight in tonnes, with the density set from your supplier's figure.
Topsoil is the one garden material where weight matters as much as volume — it is delivered by the tonne and spread by the yard. This calculator gives you both, and the density is yours to set.
The default 1,300 kg/m³ is a typical figure. If your supplier states a different density, use theirs — it is more accurate.
Your results
Enter your measurements and press Calculate.
Quantities are rounded up to whole tiles, planks, boxes or bags, after the wastage allowance. Cost appears only when you enter a price.
Formula
All lengths are converted to a single unit before the calculation: 1 ft = 0.3048 m, 1 in = 25.4 mm, 1 ft² = 0.09290304 m², 1 yd² = 9 ft². Material quantities are rounded up — you cannot buy part of a tile, plank or bag.
How to use this calculator
- Choose the shape of the area (rectangle, circle, or a known area).
- Enter the depth — 2–6 in is normal for levelling.
- Check the density against your supplier's figure (default 1,300 kg/m³).
- Add a price per cubic yard if you want a cost estimate.
Worked example
| Area | 10 ft × 20 ft = 200 ft² |
|---|---|
| Volume (4 in deep) | 200 × ⅓ ft = 66.67 ft³ = 2.47 yd³ |
| With 10% wastage | 2.47 × 1.10 = 2.72 yd³ (2.08 m³) |
| Weight (1,300 kg/m³) | 2.08 × 1,300 = 2,700 kg = 2.70 tonnes |
Check it by hand: every step above uses the formula in the box. If your numbers match the example inputs but the calculator gives a different answer, please report it via the contact page.
Frequently asked questions
How much does topsoil weigh?
It depends on the density, which varies by supplier and moisture — typically 1,200–1,400 kg/m³. This calculator defaults to 1,300 kg/m³ and lets you change it; the weight is only as good as the density you enter.
How much topsoil do I need to level a lawn?
Multiply the area by the depth. A 10 × 20 ft area levelled 4 in deep needs 2.72 yd³ — about 2.70 tonnes. Measure the low spots: the depth is the deepest fill, not the average.
Is topsoil sold by weight or volume?
Usually by volume (cubic yards or bulk bags) for gardens, and by the tonne for large jobs. This calculator gives you both, so you can compare quotes either way.
How deep should topsoil be?
2–6 in (50–150 mm) for levelling and top-dressing. For a new lawn, 4–6 in of topsoil over the subsoil is the usual minimum.
Related calculators
Estimates only. Results are for planning. Measure twice, confirm box coverage and tile sizes on the packaging you buy, and follow the manufacturer's instructions. See the disclaimer.