How to use this calculator
- Measure the length and width of the bed (for irregular beds, estimate an average rectangle).
- Choose the depth. 2–3 in (5–7.5 cm) is typical for mulch, 3–4 in for weed suppression.
- Buy bulk by the cubic yard or meter for large areas, or bags for small ones.
Formula
Volume is area × depth.
V = L × W × D
1 yd³ = 27 ft³ = 13.5 bags of 2 ft³
Example
- 20 × 4 ft bed, 3 in deep: 80 ft² × 0.25 ft = 20 ft³.
- 20 ÷ 27 = 0.74 yd³, or 10 bags of 2 ft³.
Frequently asked questions
How deep should mulch be?
2–4 in (5–10 cm). Deeper layers can suffocate roots; keep mulch a few inches away from tree trunks and stems.
How much does a cubic yard cover?
About 108 ft² at 3 in deep, or 162 ft² at 2 in deep.
Does mulch settle?
Yes, fresh bark mulch can compact 10–20%. Order a little extra for a fluffy finished depth.