Find how much compost you need in cubic yards, cubic feet and bags to top-dress beds, lawns and vegetable gardens.
How the compost calculator works
Compost improves almost any soil. Enter the area and how deep you want to spread it, and this compost calculator returns the cubic yards and the number of bags to buy.
A thin ¼–½ inch layer suits lawns and top-dressing, while new beds benefit from 2–3 inches worked in.
How to use it
- Enter the area you’re amending and choose rectangular or round.
- Set the depth — thin for top-dressing, deeper for new beds.
- Pick a bag size for a bag count, or read cubic yards for bulk.
Formula reference
volume (ft³) = area × depth
cubic yards = ft³ ÷ 27
bags = ft³ ÷ bag size (round up)
Try it with these numbers
Worked through, a length of 10, width of 10, diameter of 10 produces a material needed of 0.62. Underneath, Cubic yards comes out at 0.62 and Cubic feet at 16.7. Change any field and every figure updates as you type.
Questions people ask about this
How much compost for a vegetable garden?
Work 2–3 inches into the top few inches of soil for a new veg bed, then top up about an inch each season.
Can I use too much compost?
Yes — very thick layers every year can build up excess nutrients. A thin annual top-up is usually enough for established beds.
How many bags in a cubic yard of compost?
About 18 of the common 1.5-cubic-foot bags, or 27 one-cubic-foot bags.