How Much Compost for 100 Square Feet?

For 100 square feet of compost at 2 inches deep, you need about 0.62 cubic yards - roughly 17 bags (1 cu ft bag). The amount changes with depth; the table below shows common depths, and you can adjust everything in the calculator.

DepthCubic yardsBags
1 in0.319
2 in0.6217
3 in0.9325

Based on 100 square feet (100 sq ft). One cubic yard = 27 cubic feet; bags are 1 cu ft bag.

0.25-0.5 in to top-dress a lawn, 1-3 in to amend a bed before digging in.

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You need about

0.62cubic yards
17
bags (1 cu ft bag)

For a new or tired planting bed, spread 1 to 3 inches of compost and dig or till it into the top several inches of soil. For an established lawn, a thin quarter to half inch top-dressing is enough.

Measure the bed in feet, set the depth, and the calculator returns cubic yards and the number of bags for the size you buy.

Other compost amounts

Same area, other materials

Need a different size? Open the full Compost calculator →