Compost Calculator
How much compost do you need? Enter your area and depth.
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Cubic feet needed—
Bags (1.5 cu ft each)—
Estimated cost (bags)—
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How this calculator works
It multiplies your area by the spread depth for the volume, then shows it as cubic yards (bulk) and 1.5 cubic-foot bags.
Worked example — a 20 ft × 10 ft bed at 2 inches:
200 × (2 ÷ 12) = 33.3 cubic feet → ÷ 27 = 1.23 cubic yards, or about 23 bags.
How thick to spread compost?
A 1–2 inch top dressing is plenty for established beds; mix 2–3 inches into new beds before planting.
Frequently asked questions
How many bags of compost in a yard?
About 18 bags of the 1.5 cubic foot size make one cubic yard.
How deep should compost be?
1–2 inches as a top dressing, more when amending new soil.
Planning a landscaping project
Measure each section separately when a bed or lawn is not a perfect rectangle, then add the sections together. Depth, moisture, compaction, and the way a supplier loads material can change the final quantity, so use the result as a purchasing estimate and confirm the supplier's coverage information.
How to use this estimate
- Measure the project in the units shown and recheck your measurements before ordering.
- Use the waste allowance as a planning buffer, not as a substitute for a detailed material takeoff.
- Compare the result with the package yield, coverage, or weight listed by your supplier.
- Prices are user-entered estimates and may change by location, product, delivery, and season.
Accuracy and limitations
Calculapedia provides educational planning estimates. It does not inspect your site, select products, guarantee quantities, or replace a contractor, engineer, architect, building official, or supplier. Confirm the final quantity and any safety or code requirements before buying or building.