Compost Calculator — Cubic Yards, Weight & Bags
Calculate how much mulch, topsoil, compost or gravel you need from area and depth — cubic yards, cubic feet, estimated weight and bags to buy.
Processed entirely in your browser — nothing you enter here is ever uploaded.
Result
About this tool
This page opens the calculator with compost preselected as the material: enter your area (directly, or as length × width) and how deep you plan to spread it, and get the volume in cubic yards and cubic feet, an estimated weight, and a bag count for standard 2 cubic foot bags.
Compost sits between mulch and topsoil in density — a typical bulk density of roughly 1,000-1,100 lb per cubic yard, heavier than fluffy bark mulch but noticeably lighter than screened topsoil. Finished compost varies a lot by moisture and how well it's broken down, so this figure is a typical starting point for planning a delivery or a truck load, not an exact scale weight.
The full calculator is right here, just preconfigured for compost — switch to mulch, topsoil or gravel at any time. Every result is computed locally in your browser from static figures, with no uploads and no account needed.
Example. A 10 foot by 10 foot area at 3 inches of mulch returns 25.0 cubic feet, 0.93 cubic yards, 370 pounds, and 13 bags of 2 cubic feet.
Limit. Weight uses a single bulk density per material, 400 pounds per cubic yard for mulch, 2100 for topsoil, 1050 for compost, and 2850 for gravel.