Topsoil calculator
Whether you are filling a raised bed, spreading a lawn-leveling layer, or building a new planting area, this tool converts your dimensions into cubic yards, tons, and bags so you can compare bulk delivery against bagged soil.
How the topsoil calculator works
The calculator finds the volume of the space you are filling in cubic feet, adds a settling allowance because loose soil compacts after watering, then converts to cubic yards for bulk orders and to bags for small jobs. Weight is estimated from a typical density so you know whether a delivery or a truck rental is realistic.
Soil weight varies a lot with moisture. Dry screened topsoil runs about 1 ton per cubic yard, while wet clay-heavy soil can exceed 1.3 tons. Compost and bagged garden mixes are lighter.
Formula
cubic feet = length ft × width ft × depth in ÷ 12 × number of beds
cubic yards = cubic feet × (1 + settling %) ÷ 27
Example: two 4 × 8 ft raised beds filled 12 inches deep hold 2 × 32 = 64 cubic feet. With 15 percent for settling, that is 74 cubic feet or 2.7 cubic yards. In 40 lb bags, which hold about 0.75 cubic feet, you would need 99 bags, so a bulk delivery of 3 yards is the practical choice.
Depth guide
| Project | Depth | Notes |
|---|---|---|
| Raised vegetable bed | 10 to 12 in | Mix topsoil with a third compost. Fill the bottom of deep beds with cheaper fill. |
| New lawn from seed or sod | 4 to 6 in | Rototill into the existing grade rather than layering on top. |
| Leveling low spots in a lawn | 0.5 to 1 in per pass | Grass dies under more than an inch. Repeat in a few weeks if needed. |
| Flower or shrub bed | 6 to 8 in | Finish with 3 in of mulch from the mulch calculator. |
Common questions
How many 40 lb bags of topsoil make a cubic yard?
About 36 bags. A 40 lb bag holds roughly 0.75 cubic feet, and a cubic yard is 27 cubic feet. The exact count varies with moisture, since bags are sold by weight rather than volume.
How much does a cubic yard of topsoil weigh?
Roughly 2,000 to 2,600 pounds, or 1 to 1.3 tons. Wet soil sits at the high end. A half-ton pickup can carry about a third of a yard safely.
How much topsoil do I need for a 4x8 raised bed?
A 4 × 8 ft bed that is 12 inches deep holds 32 cubic feet, which is 1.2 cubic yards or about 43 bags of 40 lb soil. Allow 15 percent extra for settling and plan to top it up each spring.
What is the difference between topsoil and garden soil?
Topsoil is screened native soil, sold in bulk, and is best for filling, grading, and lawns. Garden soil is a bagged blend of topsoil, compost, and often peat or bark, with better drainage and nutrients for beds and containers.