Compost calculator
Work out how much compost a bed or lawn top-dressing needs.
Compost calculator
Use your supplier's density
You need
- Volume
- Weight
- Area
| Order by | Exact | Order, rounded up for anything sold in whole bags |
|---|
Enter your measurements to see what to order.
One cubic yard of compost weighs about 0.57 US tons and covers about 132 square feet at 2.5 in.
How to work out how much compost you need
- Measure the area in feet and multiply length by width.
- Pick a depth in inches and multiply it by the area to get a volume.
- Multiply the volume by the bulk density, 674 kg per cubic metre for compost, to get a weight.
- Divide the weight by your supplier's ton or cubic yard to get what to order, and round up. Suppliers do not sell part bags.
- Add 10 percent. Covers settlement, uneven ground and the material lost around the edges. A second delivery for half a yard costs more than the extra you did not use.
How many tons in a cubic yard of compost?
About 0.57 US tons, at 674 kg per cubic metre. Because published densities run from 400 to 949, the honest answer is a range: between 0.34 and 0.8 tons per cubic yard depending on grading and how wet the load is.
How many cubic yards in a ton of compost?
About 1.76 cubic yards. One tonne is about 1.48 cubic metres.
How deep should compost be laid?
| Use | Depth | What the supplier says |
|---|---|---|
| Raised bed, compost layer | 2 in to 3 in | Penn State Extension: plan on adding about two to three inches on the top and mixing it in with topsoil. Compost is a proportion of the fill rather than the whole depth. |
How much does compost weigh?
Between 400 and 949 kg per cubic metre, a spread of 137 percent. The widest band on the site. One UK supplier publishes a 50 percent internal spread, 400 to 600 kg, for the same one cubic metre bag. The calculator above uses 674, and you can replace it with your own supplier's figure.
4 published figures from 4 suppliers, read 2026-09-20.
| Supplier | Published figure | Condition |
|---|---|---|
| Premier Landscape Products LLC (Milwaukee, WI)US | 1600 LBS/YARD (800 LBS/HALF YARD) | unstated |
| J.T. Atkinson (product: AW Jenkinson Green Waste Compost)UK | 400 to 600kg (1m3) | bulk bag, unstated |
| Australian Native Landscapes (ANL)AU | Greenlife 'Mulch & Compost' 0.6 (Tonnes / Metre) | loose ('Loose Tonnes' column) |
| Severn Waste Services (Greengrow)UK | About 0.6 kg/litre or 1.6m3 per tonne | unstated |
What you can order compost in
| Pack | Where | Size |
|---|---|---|
| cubic yard | US, CA | 0.765 m3 |
| US ton | US, CA | 907 kg |
| 0.5 cu ft bag | US, CA | 0.014 m3 |
| 2 cu ft bag | US, CA | 0.057 m3 |