How Much Topsoil Do I Need for a New Lawn? Chart by Lawn Size

Lawn area × topsoil depth, plus about 10% because loose soil settles. A 1,000 sq ft lawn with 4 in of topsoil needs about 13.6 cubic yards (about 14.9 tons). A 100 m² lawn with 100 mm needs about 11 m³ (about 14.3 tonnes). At 6 in or 150 mm, it's half as much again.

Volume = lawn area × topsoil depth. Plan the depth so the finished turf sits level with paths and edges.

Topsoil by lawn size

Topsoil for a new lawn, including 10% for settling, at about 1.3 tonnes per m³
Lawn area	4 in deep	Weight	6 in deep	Weight
250 sq ft	3.4 cu yd	3.7 tons	5.1 cu yd	5.6 tons
500 sq ft	6.8 cu yd	7.4 tons	10.2 cu yd	11.2 tons
1,000 sq ft	13.6 cu yd	14.9 tons	20.4 cu yd	22.3 tons
2,000 sq ft	27.2 cu yd	29.8 tons	40.7 cu yd	44.6 tons
5,000 sq ft	67.9 cu yd	74.4 tons	101.9 cu yd	111.6 tons

Metric: topsoil or turf underlay for a new lawn, including 10% for settling
Lawn area	100 mm deep	Weight	150 mm deep	Weight
20 m²	2.2 m³	2.9 tonnes	3.3 m³	4.3 tonnes
50 m²	5.5 m³	7.2 tonnes	8.3 m³	10.7 tonnes
100 m²	11 m³	14.3 tonnes	16.5 m³	21.5 tonnes
200 m²	22 m³	28.6 tonnes	33 m³	42.9 tonnes
500 m²	55 m³	71.5 tonnes	82.5 m³	107.3 tonnes

Weights use 1.3 tonnes per m³ for loose topsoil. Damp soil weighs more, so use your supplier's figure if you're ordering by the ton or checking what a trailer can carry.

How deep should topsoil be for a new lawn?

Penn State Extension says a new lawn needs a minimum of 4 to 6 inches of good topsoil, measured after it has firmed or settled. In Australia, Lawn Solutions Australia says to spread turf underlay about 100–150 mm deep. Use the deeper end where the ground underneath is poor, such as heavy clay or builder's fill.

The RHS advises digging or rotovating the ground 20–25 cm (8–10 in) deep before laying turf, so it isn't compacted. That loosens the soil already there; it isn't a depth of new topsoil to buy.

Worked example: a 40 × 25 ft back yard

Area: 40 × 25 = 1,000 sq ft.
Depth: 4 in = 0.333 ft. Volume: 1,000 × 0.333 = 333 cu ft.
Add 10% for settling: 367 cu ft.
In cubic yards: 367 ÷ 27 = 13.6, so order 14 cubic yards, about 14.9 tons.

In metric: a 12 × 8 m garden is 96 m². At 100 mm that's 9.6 m³, or 10.56 m³ with 10%, so order 10.6 m³ (about 13.7 tonnes).

How to measure the lawn

Split the lawn into rectangles and circles, work out each and add them up. The topsoil calculator takes several areas at once.
Take off patios, paths and beds that won't be lawn.
Decide the depth before you measure levels: the soil needs to finish low enough that the turf or seedbed ends up level with paths and edges.

Bags or bulk?

A 1,000 sq ft lawn at 4 in would take 184 bags of 2 cu ft, so lawns are almost always cheaper as a bulk delivery by the yard, cubic metre or bulk bag. Bags suit patching a small area.

Common mistakes

Ordering exactly the volume. Loose soil settles once it's raked, rolled and watered.
Mixing up inches and feet. 4 in is a third of a foot, not 0.4 ft.
Forgetting the turf. Turf goes on top of the soil; it's counted separately. See how much sod you need.