Mulch & Gravel Calculator
Work out how many cubic yards or bags of mulch, gravel, topsoil or stone you need for a bed or path.
How much mulch do I need?
Cubic yards = Length (ft) × Width (ft) × Depth (in) ÷ 12 ÷ 27
A 20 × 10 ft bed covered 3 inches deep needs 20 × 10 × 3 ÷ 12 = 50 cubic feet, or 1.85 cubic yards. That is 25 bags of 2 ft³.
Recommended depths
| Material | Depth |
|---|---|
| Mulch (beds) | 2–3 in; up to 4 in for weed control |
| Pea gravel path | 2–3 in |
| Driveway gravel | 4–6 in in layers |
| Topsoil for new lawn | 4–6 in |
| Playground wood chips | 9–12 in for fall protection |
Bags or bulk?
Bagged mulch usually comes in 2 or 3 cubic foot bags; one cubic yard equals 13.5 bags of 2 ft³. Beyond about 2–3 cubic yards, bulk delivery is usually cheaper per yard. Keep mulch an inch or two away from tree trunks and house siding to avoid rot and pests.
Frequently asked questions
How many bags of mulch are in a yard?
A cubic yard is 27 cubic feet: 13.5 bags of 2 ft³ or 9 bags of 3 ft³.
How much area does a yard of mulch cover?
About 108 square feet at 3 inches deep, or 162 square feet at 2 inches.
How deep should gravel be for a path?
2–3 inches over landscape fabric for walking paths.
Last reviewed October 2026. Results are estimates; check important decisions with a qualified professional.