Find how much mulch a garden bed needs — in cubic yards, cubic metres and bags.
Volume = area × depth. A 10 × 10 ft bed mulched 3 inches deep needs 25 cubic feet — 0.93 cubic yards, or 13 bags of 2 cubic feet.
The Mulch Calculator works out how much mulch to buy for a flower bed, tree ring or border. Enter the bed's length and width (or total area) and the depth you want, and it returns the volume in cubic yards, cubic feet, cubic metres and litres, and the number of bags if you enter the bag size.
Mulch suppresses weeds, keeps soil moist and moderates soil temperature. A depth of 2–3 inches (5–8 cm) is usual; keep it a few centimetres away from plant stems and tree trunks. For gravel and sand use the Gravel Calculator.
Mulch quantity is a simple volume calculation.
| Bed and depth | Cubic yards | Cubic feet | Bags |
|---|---|---|---|
| 10 × 10 ft, 3 in deep | 0.926 cubic yards | 25 cubic feet | 13 |
| 20 × 5 ft border, 2 in deep | 0.617 cubic yards | 16.67 cubic feet | 9 |
| 500 sq ft, 3 in deep | 4.63 cubic yards | 125 cubic feet | 63 |
| 4 × 2 m, 5 cm deep (50 L bags) | 0.523 cubic yards | 14.13 cubic feet | 8 |
| Depth | Area covered per cubic yard |
|---|---|
| 1 in (2.5 cm) | 324 sq ft (30 m²) |
| 2 in (5 cm) | 162 sq ft (15 m²) |
| 3 in (7.5 cm) | 108 sq ft (10 m²) |
| 4 in (10 cm) | 81 sq ft (7.5 m²) |
Apply 2–3 inches (5–8 cm) of mulch for most beds. Fine mulches should be thinner than coarse ones. Too deep can suffocate roots, so avoid piling mulch against trunks (“mulch volcanoes”). Top up yearly as it decomposes.
Multiply the bed's area by the depth you want, then convert to cubic yards or bags. A 100 sq ft bed at 3 in deep needs 25 cubic feet.
About 108 sq ft at 3 in deep, 162 sq ft at 2 in, or 324 sq ft at 1 in.
A cubic yard is 27 cubic feet, so 13.5 bags of 2 cubic feet.
2–3 in (5–8 cm) for most garden beds. Use less for fine mulch and keep it away from stems.
1,000 litres. A 50-litre bag therefore covers 0.05 m³.
Yes — choose “Total area” if you already know the area in sq ft or m².
Use the Square Footage Calculator (circle) to get the area, then enter it here.
Yes, it decomposes and compacts, so top up each year and consider ordering 5–10% extra.
Per bag, per cubic yard or per cubic metre, depending on how your supplier prices it.
No. Everything runs in your browser.
