Mulch Bed Calculator
Find the cubic yards of mulch and the number of 2-cubic-foot bags for a garden bed by length, width and depth.
How it works
cubic yards = length × width × (depth ÷ 12) ÷ 27 · bags = ceil(cubic feet ÷ 2)
Mulch volume is length times width times depth (in feet) divided by 27 for cubic yards; dividing the cubic feet by 2 gives the number of standard 2-cubic-foot retail bags. This assumes a simple rectangle — for an L-shaped or curved bed, break it into rectangles, compute each, and add the volumes together before ordering.
Worked example
A 20 × 8 ft bed at 3 in deep: 20 × 8 × (3 ÷ 12) = 40 cu ft, ÷ 27 = 1.48 cubic yards, or 20 two-cubic-foot bags.
Frequently asked questions
How deep should mulch be?
2–3 in for most beds — enough to hold moisture and block weeds without smothering roots. Keep it pulled back a couple of inches from tree trunks and plant stems; piled-up “mulch volcanoes” invite rot and pests.
How do I handle an L-shaped or curved bed?
Split it into rectangles, calculate each one, and add the volumes. For curves, measure the average width and treat the section as a rectangle — the small over-estimate just becomes useful spare.
Bags or bulk?
Bags are easy for small beds and no delivery fee, but bulk mulch by the cubic yard is dramatically cheaper past about 6 yards (roughly 80 bags). Factor in delivery and whether you can move a pile with a wheelbarrow.
Related calculators
Estimates only — add for waste and confirm against local building codes and supplier specs.