Compost Calculator
Estimate how much compost you need to amend or topdress your beds.
Shape
Units
Area: 0.0 sq ft
Planning more than one thing? Open the Yard Planner → to trace your whole yard over an aerial photo and total every material at once.
How to measure for compost
- Measure the length and width of your area in feet.
- Multiply them for square feet (or just enter length and width above).
- Choose a depth — we default to 2 inches for compost.
- Read your total in cubic yards, or the number of bags.
Compost coverage at a glance (2" deep)
| Area (sq ft) | Cubic yards | Bags |
|---|---|---|
| 100 | 0.7 | 19 |
| 200 | 1.4 | 37 |
| 300 | 2.0 | 56 |
| 500 | 3.4 | 92 |
| 1,000 | 6.8 | 184 |
Includes a 10% overage allowance. Estimates are low-fi — confirm with your supplier.
Frequently asked questions
How much compost do I need?
A 1–2 inch layer is typical for topdressing or amending soil. Enter your area and depth above for an exact estimate.
How much compost for a new garden bed?
To amend a new bed, mix in 2–3 inches of compost into the top 6–8 inches of soil. Use the calculator above with your bed size and that depth.
Bags or bulk?
Bagged compost is usually about 1 cubic foot. Bulk compost (by the cubic yard) is cheaper for larger projects.