Area and volume are different measurements
Square feet and square metres describe surface area. Cubic feet, cubic yards, cubic metres and litres describe volume. Topsoil purchasing requires volume because depth must be included.
| Conversion | Calculator factor | Use |
|---|---|---|
| 1 cubic yard | 27 cubic feet | US bulk topsoil orders |
| 1 cubic yard | 0.764554858 cubic metres | US-to-metric volume |
| 1 cubic metre | 1.30795062 cubic yards | Metric-to-US volume |
| 1 cubic metre | 1,000 litres | Bag and metric comparisons |
| 1 cubic foot | 28.316846592 litres | US bag-volume conversion |
| 1 inch | 0.0254 metre | Depth conversion |
Convert inputs before multiplying
If length and width are in feet but depth is in inches, convert depth to feet before calculating cubic feet. The same principle applies when area is square metres and depth is centimetres: convert depth to metres before multiplying.
Round at the end
Keep full conversion precision during calculations and round the final display or purchase quantity. NIST guidance notes that accurate unit conversion requires the appropriate conversion factor, significant digits and rounding, and its measurement tables advise performing rounding only once after other operations where practical.
Supplier units still govern the purchase
A mathematically precise cubic-metre result may need to be purchased as whole bags, half-yard increments or a supplier-defined truckload. The final step is therefore commercial rounding, which should remain separate from the underlying conversion.