This mulch calculator works out how much mulch you need for a garden bed in cubic yards, cubic meters and bags. Enter the bed size, the depth you want and the bag size you plan to buy.
How mulch is calculated
Cubic feet = length (ft) × width (ft) × depth (in) ÷ 12, and cubic yards = cubic feet ÷ 27.
In metric, cubic meters = length (m) × width (m) × depth (cm) ÷ 100.
Worked example
A 20 × 10 ft bed covered 3 inches deep needs 50 cubic feet, which is about 1.85 cubic yards or 25 bags of 2 cubic feet.
Frequently asked questions
How deep should mulch be?
Two to three inches (5–8 cm) is a common recommendation for garden beds. Keep mulch a few inches away from tree trunks and plant stems.
Is bulk or bagged mulch cheaper?
For more than a cubic yard or two, bulk delivery is usually cheaper per yard. Bags are easier for small beds.