Soil Calculator

A soil volume calculator determines how much topsoil, compost, or mulch to order for a garden area at a target depth, converting to bags or tonnes for purchasing. Use this calculator for accurate, instant results.

The calculator uses the standard published formula for soil volume. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

This calculator works with inches, percentages, watts. You can enter values in the units shown — the calculator handles all conversions internally.

The core formula is: Volume = Length × Width × Depth (all metres). Each step in the calculation is shown so you can verify the result manually.