How to use this calculator
- Enter Area in sq ft.
- Enter Depth in in — or tap a preset badge to auto-fill a typical value.
- Press Calculate. The highlighted row is your order quantity; the note beneath it translates the number into real-world terms.
Formula & constants
Topdressing lawns: 1/4–1/2 in (one yard covers 300–650 sq ft). Amending beds: 2–3 in tilled into the top 6–8 in of native soil. Every default in the fields above is editable — when your supplier’s spec sheet lists a different density, coverage rate or price, enter that number instead. The waste and compaction allowances follow common trade practice; see our methodology page for the derivation of each formula and the standards it references.
Where this fits in the project
Hardscape follows the same layer logic as paving: excavate, place compacted base and bedding sand, then set surface units. Bulk organics like mulch and topsoil are ordered by the cubic yard.
How this connects to your project
No quantity stands alone — each material in the chain depends on the ones around it. These are the planning steps that pair with the compost calculator:
- Topsoil Calculator — Compost is mixed into topsoil as an amendment.
- Mulch Calculator — Compost can serve as a nutrient-rich mulch layer.
- Fertilizer Calculator — Compost provides natural nutrients vs synthetic fertilizer.
- Grass Seed Calculator — Compost is mixed with soil before seeding.
- Sod Calculator — Compost is tilled in before sod installation.
Frequently asked questions
Can I plant in pure compost?
No — it’s an amendment, not a soil. Blend 25–35% compost into native soil; pure compost drains poorly and slumps.
How much compost to topdress a lawn?
1/4–1/2 in raked in after aeration — about 1 cu yd per 400 sq ft at the heavier rate.
Last verified: — prices reflect current national averages. See our methodology.
Estimates are for planning. Material densities, coverage rates and prices vary by region and supplier — confirm final quantities before ordering, and check local code where structural or electrical work is involved.