Enter garden details
How it works
Compost volume = bed area × compost depth. The calculator then adds your selected allowance and converts the purchase volume into common buying units.
Planning estimates depend on your measurements, product labels, material density and site conditions. For purchased products, follow the manufacturer's label.
Your result summary
Results are calculated from the values you enter. Volume conversions use standard metric/US customary relationships. Bag counts are rounded up when shown.
How to use this calculator
What to enter
Enter or select the following as requested: Unit system; Bed / area shape; Length; Width; Diameterfor circular beds; Compost depthcm or in; Extra allowance%; Bag size (litres)L or ft³. Follow the units, valid ranges, examples, and options displayed beside each field.
What the result means
The result estimates the soil, plant, water, or landscape quantity from the area, dimensions, spacing, flow, or rate entered. Check whether the tool includes settling, runoff, germination, overlap, or waste allowances.
When to use it
Use this to plan garden or landscape materials and quantities. Verify measurements on site and adapt estimates to soil type, plant requirements, local rainfall, and product instructions.