Soil Calculator

How much soil do you need? Enter your bed's size and depth to get cubic feet, cubic yards and bags required.

100% FreeNo sign-upPrivate — runs in your browser
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Soil volume
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Soil volume
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Bags needed (rounded up)
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Bed area
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How to use this tool

1
Measure the bed

Length and width in feet, at the widest points if the bed is irregular — use the average for odd shapes.

2
Choose the depth

Vegetables usually want 6–12 inches of soil, lawns 4–6 inches, and raised beds whatever their wall height is.

3
Read the volume

The headline figure is cubic feet; cubic yards beside it is what bulk suppliers sell by (1 cubic yard = 27 cubic feet).

4
Buy the bags

Bags are rounded up, never down — a half bag short is worse than one spare bag, and soil settles by 10–20% after watering.

Formula & worked example

Volume (cu ft) = length (ft) × width (ft) × depth (in) ÷ 12. Cubic yards = cubic feet ÷ 27. Bags = volume ÷ bag size, rounded up.

A 10 ft × 4 ft bed filled 6 inches deep needs 10 × 4 × 6 ÷ 12 = 20 cubic feet, which is 0.74 cubic yards, or 10 bags of 2 cubic feet each.

Limitations — read this before you rely on it

Soil settles and compacts after watering, typically by 10–20%, so buying exactly the calculated volume often leaves the bed low — many gardeners add about 10% extra. For irregular beds, containers or mounds this rectangular calculation is an approximation; measure in sections and add them up for better accuracy.

Frequently asked questions

About 6–12 inches for most vegetables and flowers, 4–6 inches for a new lawn, and the full height of a raised bed. Deeper is better for root crops like carrots.

27. Bulk soil is sold by the cubic yard, bags by the cubic foot — divide cubic feet by 27 to convert.

Yes, roughly 10% extra, or buy one spare bag. Freshly spread soil settles noticeably after the first few waterings.

Approximately: use the diameter as both length and width, then multiply by 0.785 (π ÷ 4) to correct the square into a circle.

Measure only the depth you are adding, not the total bed depth — or subtract the existing soil depth from your target depth first.