Answer first
What this calculator tells you
Calculate the cubic yards, bags and tons of topsoil needed for a lawn, a garden or a raised bed. Decide between bulk delivery and bags, and order the right weight for a truck. Formula: Cubic yards = area × depth (in) ÷ 12 ÷ 27; bags = cubic feet ÷ bag size; tons = cubic yards × weight per cubic yard. At the worked-example inputs, the topsoil needed (cubic yards) is 6.2. Holding every other input steady, moving area to cover (sq ft) from 400 to 600 moves the result from 4.9 to 7.4.
Transparent method
The formula
Decide between bulk delivery and bags, and order the right weight for a truck.
Worked example
Example inputs
How to interpret the result
Topsoil is bought by volume and by weight. A 500 square foot lawn at 4 inches deep needs 166.7 cubic feet, or 6.2 cubic yards. At about 1.1 tons a yard, that is close to 6.8 tons, which is a real load for a truck and a driveway.
At the worked-example inputs the topsoil needed (cubic yards) is 6.2. It rises with soil depth (in) and area to cover (sq ft); bag size (cu ft) and weight per cubic yard (tons) do not move it.
These are quantity estimates from the area and depth you enter. Real yards have slopes, curves and settling, and bulk materials vary in weight with moisture, so order a little extra and confirm coverage, bag sizes and rates with the product label or your supplier. Fertilizer and seed rates depend on your grass, soil and region, so follow the label and your local extension office.
Before you rely on it
What to check
Ask the supplier for the weight per cubic yard of the actual pile. Wet topsoil can weigh a third more than dry, and a delivery is billed by the yard but limited by the ton.
The common error
Where people go wrong with topsoil calculator
Ordering for the finished depth only. Loose soil settles by 10 to 20 percent after watering, so add a little extra for a bed that has to reach a set height.
Sensitivity evidence
How area to cover (sq ft) changes the topsoil needed (cubic yards)
Holding every other input at the worked-example value, moving area to cover (sq ft) from 400 to 600 moves the topsoil needed (cubic yards) from 4.9 to 7.4: a spread of 2.5, or 40% of the worked-example result.
| Area to cover (sq ft) | Topsoil needed (cubic yards) | Bags needed | Weight (tons) |
|---|---|---|---|
| 400 | 4.9 | 178 | 5.4 |
| 450 | 5.6 | 200 | 6.1 |
| 500worked example | 6.2 | 223 | 6.8 |
| 550 | 6.8 | 245 | 7.5 |
| 600 | 7.4 | 267 | 8.1 |
Every input, tested
Which input moves the topsoil needed (cubic yards) most
Of the 4 inputs, soil depth (in) moves the topsoil needed (cubic yards) most (1.2 across the range tested) and area to cover (sq ft) moves it least (1.2). Bag size (cu ft) and weight per cubic yard (tons) do not change it at all.
| Input | Tested from | To | Topsoil needed (cubic yards) at each end | Swing |
|---|---|---|---|---|
| Soil depth (in) | 3.6 | 4.4 | 5.6 to 6.8 | 1.2 (20%) |
| Area to cover (sq ft) | 450 | 550 | 5.6 to 6.8 | 1.2 (20%) |
| Bag size (cu ft) | 0.68 | 0.83 | 6.2 to 6.2 | none |
| Weight per cubic yard (tons) | 0.99 | 1.2 | 6.2 to 6.2 | none |
Two variables at once
Topsoil needed (cubic yards) by area to cover (sq ft) and soil depth (in)
Across the grid the topsoil needed (cubic yards) runs from 4 to 8.9. Moving area to cover (sq ft) from 400 to 600 shifts it by 2.5 at the middle column, and moving soil depth (in) from 3.2 to 4.8 shifts it by 2.5 at the middle row, so neither is the bigger lever here.
| Area to cover (sq ft) \ Soil depth (in) | 3.2 | 4 | 4.8 |
|---|---|---|---|
| 400 | 4 | 4.9 | 5.9 |
| 450 | 4.4 | 5.6 | 6.7 |
| 500 | 4.9 | 6.2 | 7.4 |
| 550 | 5.4 | 6.8 | 8.1 |
| 600 | 5.9 | 7.4 | 8.9 |
The highlighted cell is the worked example: 6.2.
Step by step
The worked example, input by input
| Input | Value used | What it means |
|---|---|---|
| Area to cover (sq ft) | 500 | Enter the area to cover (sq ft) used in this calculation. |
| Soil depth (in) | 4 | About 4 inches for a new lawn and 6 to 12 inches for a raised bed or garden. |
| Bag size (cu ft) | 0.75 | Retail bags of topsoil often hold 0.75 to 1 cubic foot. |
| Weight per cubic yard (tons) | 1.1 | A planning value. Moist topsoil weighs more, so ask the supplier. |
| Topsoil needed (cubic yards) | 6.2 | |
| Bags needed | 223 | |
| Weight (tons) | 6.8 | |
Inputs, definitions and assumptions
Area to cover (sq ft)
Enter the area to cover (sq ft) used in this calculation. The prefilled worked-example value is 500.
Soil depth (in)
About 4 inches for a new lawn and 6 to 12 inches for a raised bed or garden. The prefilled worked-example value is 4.
Bag size (cu ft)
Retail bags of topsoil often hold 0.75 to 1 cubic foot. The prefilled worked-example value is 0.75.
Weight per cubic yard (tons)
A planning value. Moist topsoil weighs more, so ask the supplier. The prefilled worked-example value is 1.1.
How to use this calculator
- 1Verify the inputs. Gather area to cover (sq ft), soil depth (in), bag size (cu ft) and weight per cubic yard (tons) from your own documents; the prefilled values are examples.
- 2Save a baseline. The worked example puts the topsoil needed (cubic yards) at 6.2. Store your own version of it as Scenario A.
- 3Test one change. Start with soil depth (in), the input with the biggest effect here: moving soil depth (in) from 3.6 to 4.4 takes the topsoil needed (cubic yards) from 5.6 to 6.8, a swing of 20% of the worked-example figure.
- 4Check the extremes. At half the example soil depth (in) (2) the topsoil needed (cubic yards) is 3.1; at double (8) it is 12.3.
People also ask
Frequently asked questions
How do you calculate topsoil?
Cubic yards = area × depth (in) ÷ 12 ÷ 27; bags = cubic feet ÷ bag size; tons = cubic yards × weight per cubic yard. At the worked-example inputs the topsoil needed (cubic yards) is 6.2.
What does the topsoil result mean?
Decide between bulk delivery and bags, and order the right weight for a truck. At the worked-example inputs the topsoil needed (cubic yards) is 6.2. It rises with soil depth (in) and area to cover (sq ft); bag size (cu ft) and weight per cubic yard (tons) do not move it.
How much does area to cover (sq ft) change the topsoil needed (cubic yards)?
Holding every other input at the worked-example value, moving area to cover (sq ft) from 400 to 600 moves the topsoil needed (cubic yards) from 4.9 to 7.4, a spread of 2.5.
What are the limits of this topsoil calculator?
These are quantity estimates from the area and depth you enter. Real yards have slopes, curves and settling, and bulk materials vary in weight with moisture, so order a little extra and confirm coverage, bag sizes and rates with the product label or your supplier. Fertilizer and seed rates depend on your grass, soil and region, so follow the label and your local extension office. The tables on this page test area to cover (sq ft) only from 400 to 600; a value outside that range is not tabulated here.
Which input moves the topsoil needed (cubic yards) most in the topsoil calculator?
Ranked by how far each moves the topsoil needed (cubic yards) across the range tested: soil depth (in) (1.2, 20%) and area to cover (sq ft) (1.2, 20%). Bag size (cu ft) and weight per cubic yard (tons) do not change it.
If I double soil depth (in) in the topsoil calculator, does the topsoil needed (cubic yards) double?
Doubling it from 4 to 8 takes the topsoil needed (cubic yards) from 6.2 to 12.3, which is 2.00 times the worked-example figure. So the result scales almost exactly in proportion. Halving it to 2 gives 3.1.
How much does soil depth (in) matter in the topsoil calculator?
The worked example uses 4. Holding every other input at its worked-example value, moving soil depth (in) from 3.6 to 4.4 takes the topsoil needed (cubic yards) from 5.6 to 6.8, a swing of 20% of the worked-example figure.
How much does bag size (cu ft) matter in the topsoil calculator?
The worked example uses 0.75. The topsoil needed (cubic yards) does not depend on bag size (cu ft); it moves the bags needed from 246 to 201 instead when bag size (cu ft) goes from 0.68 to 0.83.
How much does weight per cubic yard (tons) matter in the topsoil calculator?
The worked example uses 1.1. The topsoil needed (cubic yards) does not depend on weight per cubic yard (tons); it moves the weight (tons) from 6.1 to 7.5 instead when weight per cubic yard (tons) goes from 0.99 to 1.2.
Which inputs change the bags needed in the topsoil calculator?
At the worked-example inputs it is 223. Area to cover (sq ft) takes it from 200 to 245, soil depth (in) takes it from 200 to 245 and bag size (cu ft) takes it from 246 to 201.
Which inputs change the weight (tons) in the topsoil calculator?
At the worked-example inputs it is 6.8. Area to cover (sq ft) takes it from 6.1 to 7.5, soil depth (in) takes it from 6.1 to 7.5 and weight per cubic yard (tons) takes it from 6.1 to 7.5.
Do bulk materials settle after delivery?
Yes. Soil and mulch settle by 10 to 20 percent and stone compacts by about 10 to 15 percent, so round the order up rather than down.
Why is the tonnage different from what I expected?
Weight per cubic yard depends on the material and its moisture. Gravel is about 1.3 to 1.6 tons, sand about 1.3 to 1.4 and topsoil about 1.1, and rain adds to all of them.
How much water does a lawn need?
About 1 inch a week, counting rain, is a common target for cool-season grass. Water deeply two or three times a week rather than a little every day, so roots grow down.
Sources and evidence
Free Calculators Online is independent and is not affiliated with or endorsed by the source organizations. Educational estimates only.