Raised Bed Soil Calculator
Find how much soil your garden beds need — in cubic feet, cubic yards, and bags.
Results are estimates for planning. Soil settles after watering — fill slightly proud of the top and plan to top up.
How to Measure a Raised Bed
Soil volume comes straight from the inside dimensions of the bed.
Rectangular beds
Measure the inside length and width in feet and the fill depth in inches. Set the quantity if you're filling several identical beds at once.
Round beds and planters
For a circular bed or planter, switch to the Round tab and enter the inside diameter and the fill depth.
Common Mistakes to Avoid
- Filling to the exact rim. Soil settles — slightly overfill so the level stays right after watering.
- Buying all bagged soil. Beyond about a cubic yard, bulk soil is far cheaper than bags.
- Too shallow for the crop. Root vegetables need 12-18 inches; a shallow bed limits what you can grow.
- Pure topsoil. Raised beds do best with a blend of topsoil, compost, and aeration — not heavy soil alone.
Frequently Asked Questions
Multiply length × width × depth in feet. A 4×8 ft bed filled 12 inches deep needs 32 cubic feet of soil.
A 32 cu ft bed needs about 22 of the 1.5 cu ft bags, or 16 of the 2 cu ft bags.
6-12 inches suits most plants; deep-rooted crops prefer 12-18 inches.
Bagged for one or two small beds; bulk by the cubic yard is much cheaper beyond about a cubic yard.
Yes — fill slightly over the rim and top up after the first watering or rain.