The Mulch Calculator estimates how much mulch, compost or topsoil you need, in cubic yards, cubic feet and bags.
Mulch needed: 1.85 cubic yards
| Cubic yards | 1.85 |
| Cubic feet | 50 |
| Cubic meters | 1.42 |
| Bags of 2 cu ft | 25 |
Mulch needed: 0.73 cubic yards
| Cubic yards | 0.73 |
| Cubic feet | 19.63 |
| Cubic meters | 0.56 |
| Bags of 2 cu ft | 10 |
Volume = length × width × depth. Convert everything to feet, then divide cubic feet by 27 to get cubic yards, the unit bulk mulch is sold in.
Worked example (defaults): a 20 × 10 ft bed at 3 inches deep needs 50 cubic feet, about 1.85 cubic yards or 25 two-cubic-foot bags.
Fine mulch: 2 inches. Coarse mulch and wood chips: 3–4 inches. Keep mulch a few inches away from tree trunks and plant stems to prevent rot ("volcano mulching" harms trees).
Mulch keeps soil moist, suppresses weeds, moderates soil temperature, reduces erosion and, as organic mulch breaks down, improves the soil.
Bags or bulk? Bulk is cheaper for more than about 2 cubic yards.
How often should I re-mulch? Top up about once a year.
How much does a cubic yard cover? About 108 sq ft at 3 inches.