Compost Calculator

Compost Calculator

Cubic yards and bag counts for garden beds, soil amendment, lawn top dressing, and raised bed mixes.

How Much Compost Do You Actually Need?

Compost depth depends entirely on what you're using it for. A lawn top dressing only needs ¼ to ½ inch — but spread over a 2,000-square-foot lawn, that thin layer adds up to 1.5 to 3 cubic yards. Amending existing garden beds typically calls for 2–3 inches mixed into the top 6–8 inches of soil. And if you're filling brand-new raised beds, compost should make up 30–40% of the total fill volume, blended with topsoil.

The Compost Calculator shows cubic yards for bulk delivery and bag counts for pickup. Bulk compost from a landscape supplier runs $20–$40 per cubic yard — significantly cheaper than bagged compost from a home center, which works out to $120–$180 per cubic yard in 1-cubic-foot bags. For anything over half a cubic yard, bulk delivery almost always makes more sense.

Compost pairs with garden soil in raised beds and topsoil for lawn improvement projects. Once your beds are planted and amended, a layer of mulch on top retains the moisture that makes compost effective. For established lawns, compost top dressing before overseeding is one of the most effective soil improvement techniques — just keep the layer thin enough that grass can grow through it.