Mulch Calculator

Calculate Mulch Needed

How mulch volume is calculated

Mulch is sold by volume, not weight, so the math is area times depth:

Cubic feet = length (ft) × width (ft) × depth (in) ÷ 12
Cubic yards = cubic feet ÷ 27

One cubic yard covers about 108 sq ft at 3 inches deep, 81 sq ft at 4 inches, or 162 sq ft at 2 inches. Bagged mulch is usually sold in 2 cu ft or 3 cu ft bags, so 13–14 of the 2 cu ft bags equal roughly one cubic yard.

How deep should mulch be? Two to three inches is the standard for established landscape beds — enough to hold moisture and discourage weeds without smothering roots. Four inches suits a brand-new bed or bare soil. Around trees, keep mulch a few inches away from the trunk (no "mulch volcanoes") — piling it against bark traps moisture and invites rot.

Bags or bulk? For anything over about a cubic yard, bulk delivery is usually far cheaper per cubic foot and saves a lot of plastic and trips. Under half a yard, bags are more convenient and easier to place precisely. If you're between, remember mulch settles and compacts after the first rains — ordering about 10% extra avoids a thin-looking finish.

Odd-shaped beds? Break the bed into rectangles (and triangles at half the rectangle's area), calculate each, and add them together.