Mulch Calculator
Calculate cubic yards of mulch for garden beds and tree rings. Optional bag count when you know bag volume.
Assumptions
- Mulch is spread at a uniform depth across the bed.
- Typical decorative depth is 2–4 inches; refresh layers may be 1–2 in.
- Bag volume defaults to 2 ft³ per bag when enabled.
- Settled volume is less than fluffed delivery — order by installed depth.
- Does not include edging or weed barrier materials.
Volume = area × depth (converted to consistent units). Cubic yards = volume ÷ 27 (from ft³). Ordered volume includes waste percentage.200 ft² bed, 3 in depth
- Depth 3 in = 0.25 ft. Volume = 200 × 0.25 = 50 ft³. Cubic yards = 50 ÷ 27 ≈ 1.85 yd³. With 10% waste ≈ 2.0 yd³.
How to measure
Outline the bed and measure length × width, or break irregular beds into rectangles. Depth is the thickness you will spread after settling — not the piled height from the truck.
Common mistakes
- Confusing inches of depth with feet.
- Underestimating irregular curved beds — break into sections.
- Ordering by bag count without checking bag cubic feet (2 vs 3 ft³ bags differ).
Frequently asked questions
How deep should mulch be?
2–3 in for maintenance, 3–4 in for new beds. More than 4 in can harm plant stems.
Bags vs bulk delivery?
Bulk by the cubic yard is economical above ~2 yd³. Bags are easier for small beds.
Does mulch type change volume?
Volume is the same; density varies. This calculator uses volume, not weight.
How often to refresh?
Most beds need 1–2 in added annually as mulch decomposes.