Category: Calculators
Soil Calculator
Work out how much topsoil or potting soil a bed needs
Enter the length, width and depth of a bed or planter to estimate the soil volume needed, and optionally the number of bags.
Length, width and depth must all use the same unit; the volume is in that unit cubed. Bag count only appears once a bag volume above zero is entered, in that same cubic unit.
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What this tool does
The calculator multiplies length by width by depth to get the volume, then adds your waste percentage for settling and an uneven base. If you also enter the volume one bag holds, the calculator divides the volume needed by that bag size and rounds up to a whole bag.
How to use it
- Enter the length, width and depth of the bed or planter in one consistent unit.
- Enter a waste percentage for settling and an uneven base.
- Optionally enter the volume one bag of soil holds.
- Read the volume needed, and the bag count if you entered a bag size.
Privacy
This tool runs entirely in your browser. Your input is never uploaded, stored or shared — closing the tab removes it.
Frequently asked questions
- How deep should garden soil or topsoil be?
- 6 to 12 inches (about 15 to 30 cm) is typical for a new planting bed; raised beds and planters usually need to be filled to their full depth instead.
- Does this work for potting soil in containers?
- Yes, enter the container's length, width and fill depth; for round pots, treat length and width as the same value for a simple estimate.
- Should I allow extra soil for settling?
- 5 to 15% is common, since new soil compacts after watering; deeper beds and looser soil mixes usually settle more.