Topsoil Calculator
This topsoil calculator finds how much soil you need from the bed area and the depth. Enter them and the topsoil calculator returns the volume in cubic metres, cubic yards, and bags. As a topsoil estimator it answers how much topsoil you need for a garden, lawn, or raised bed in one step.
Results
The Topsoil Calculator is part of our Materials Estimating collection. Browse more materials estimating to size, convert, and check your work alongside this tool.
What the topsoil calculator shows
Topsoil is sold by volume, so the topsoil calculator turns the area of your beds and the depth you want into a volume. It reports cubic metres, cubic yards for a bulk load, and the number of bags for a bagged order. Whether you run it as a topsoil estimator, a soil calculator by yards, or a how much dirt do I need calculator, it answers how much topsoil you need.
How the topsoil estimator finds the volume
The topsoil estimator multiplies the area by the depth for a volume, then converts to yards or bags:
One cubic yard of soil is about 764 liters and 27 cubic feet, so the topsoil calculator divides the volume by the bag size for the bag count. Depth is the lever: doubling the depth doubles the soil, which is why a cubic yards of soil calculator always asks how deep you want it.
Soil calculator yards example
A bed 10 m by 5 m at a 100 mm depth. The soil calculator by yards gives:
At 40 liters a bag that is about 125 bags. Enter your own beds and the topsoil calculator updates the yards and bags at once.
How to use the topsoil calculator
Enter the bed length and width in metres, the depth in millimeters, and the bag size, then the topsoil calculator returns the volume and the bag count. A 100 to 150 mm layer suits new beds and lawns; a raised bed is deeper. To work out how much topsoil you need for several beds, add their areas first, or run each bed and total the results.
Reading the topsoil calculator result
Order bulk soil by the cubic yard and bagged soil by the bag; both already include your chosen depth. Round up a little, since beds settle and are rarely perfect rectangles. Bulk topsoil is far cheaper per yard than bags once you pass about ten to fifteen bags, so a topsoil calculator by yards helps you choose which to buy. Screened topsoil packs tighter than rough fill, so allow a little extra if it will be compacted.
When you ask how much topsoil do I need
- Topping garden beds and lawns when you ask how much topsoil do I need
- Filling a raised bed with the topsoil estimator
- Ordering a bulk load with a cubic yards of soil calculator
- Buying bags with a how much dirt do I need calculator
Common topsoil calculator mistakes
- Guessing the area. Break odd beds into rectangles and add them before you calculate the soil.
- Ignoring settling. Screened soil compacts, so add 10 to 20 percent if it will be firmed.
- Buying bags for a big job. Bulk by the yard is cheaper once you pass ten to fifteen bags.
Tips for ordering topsoil
- Use 100 to 150 mm for beds and lawns.
- Total all beds and convert once to avoid over ordering.
- Order bulk by the yard once you pass ten to fifteen bags.
How much topsoil do I need by area and depth
Every soil order comes down to area and depth, and measuring the area well is where people slip. Measure each bed as length times width, break curved or L shaped beds into rectangles, and add them before you divide. A topsoil calculator by yards is only as good as that area. Depth then scales the volume directly, so the same bed at 150 mm needs half again what it needs at 100 mm. To figure out how much topsoil you need for a whole yard, total all the beds first, then convert once; running each bed separately and rounding each up wastes soil. Screened topsoil settles and compacts, so add roughly 10 to 20 percent if the soil will be firmed down.
Cubic yards of soil calculator and bags
A cubic yards of soil calculator and a bag count answer the same volume in two units. One cubic yard is about 764 liters and 27 cubic feet, so a 40 liter bag is roughly a nineteenth of a yard. That is why a yard of topsoil spreads over about 81 sq ft at a 4 inch depth. Bulk delivery is cheaper per yard once you pass ten to fifteen bags, and it saves carrying, but bags suit small top ups and tight access. Weight matters for delivery too: a cubic yard of topsoil is roughly a tonne, more when wet, so check access before ordering a big load. For mulch over the finished soil, the mulch calculator sizes the top layer.
How much does a yard of topsoil cover
Coverage of one cubic yard of topsoil at common depths, a quick topsoil coverage guide:
| Depth | Coverage per cubic yard |
|---|---|
| 25 mm (1 in) | 324 sq ft |
| 50 mm (2 in) | 162 sq ft |
| 100 mm (4 in) | 81 sq ft |
| 150 mm (6 in) | 54 sq ft |
Topsoil Calculator FAQ
How much topsoil do I need?
Multiply the bed area by the depth for a volume, then convert to yards or bags. For 50 m² at 100 mm you need about 5 m³, which the topsoil calculator turns into yards and bags.
How many cubic feet of soil in a yard?
27 cubic feet make one cubic yard, which is about 764 liters. That is why a yard covers about 81 sq ft at a 4 inch depth.
How many bags of soil in a cubic yard?
It depends on the bag size. At 40 liters a bag there are about 19 bags in a cubic yard; at 25 liters, about 30.
How deep should topsoil be?
About 100 to 150 mm for new beds and lawns, deeper for a raised bed. The topsoil calculator scales the amount with whatever depth you set.