Mulch
How Much Does a Yard of Mulch Cover?
One cubic yard of mulch covers 108 square feet at 3 inches deep and 162 square feet at 2 inches. Divide 324 by the depth in inches for any other depth.
By Kumar Baniya, MEng in Structural Engineering (University of Leeds) · Published
How many square feet does a yard of mulch cover?
108 square feet at 3 inches deep. A cubic yard is 27 ft³ and 3 in is a quarter of a foot, so 27 ÷ 0.25 = 108. The general rule is square feet = 324 ÷ depth in inches.
How far does a yard of mulch go at different depths?
| Depth | Square feet per cubic yard | Example bed |
|---|---|---|
| 1 in | 324 | 32.4 ft × 10 ft |
| 2 in | 162 | 16.2 ft × 10 ft |
| 3 in | 108 | 10.8 ft × 10 ft |
| 4 in | 81 | 8.1 ft × 10 ft |
How many yards of mulch do I need for my beds?
Cubic yards = square feet × depth (in) ÷ 324. For common bed sizes:
| Bed area | At 2 in | At 3 in |
|---|---|---|
| 50 sq ft | 0.31 yd³ | 0.46 yd³ |
| 100 sq ft | 0.62 yd³ | 0.93 yd³ |
| 200 sq ft | 1.23 yd³ | 1.85 yd³ |
| 500 sq ft | 3.09 yd³ | 4.63 yd³ |
| 1,000 sq ft | 6.17 yd³ | 9.26 yd³ |
For irregular beds or tree rings, add each shape separately in the mulch calculator; it also handles topping up an existing layer.
How deep should mulch be spread?
The University of Maryland Extension advises keeping mulch shallow, from one to three inches, and keeping it about three inches away from the base of tree trunks. Depths in the tables above are for the arithmetic; follow guidance for your plants.
How much do 2 or 3 yards of mulch cover?
Multiply the single-yard coverage: 2 yards cover 216 sq ft at 3 in (324 sq ft at 2 in), and 3 yards cover 324 sq ft at 3 in (486 sq ft at 2 in).
How much mulch for a tree ring?
Measure the ring as a circle minus the bare centre. A ring 6 ft across with a 1 ft clear space around the trunk is π × (3² − 0.5²) = 27.5 sq ft; at 3 in deep that is 6.87 ft³ = 0.25 yd³, or 4 bags of 2 cu ft.
How do I calculate a top-up over old mulch?
Only the missing depth needs new mulch: new depth = target − existing. Topping a 3 in target over 1.5 in of old mulch needs 1.5 in, so a yard covers 324 ÷ 1.5 = 216 sq ft. The mulch calculator has a top-up mode that never goes below zero.
Related calculations
To turn yards into bags, see how many bags of mulch are in a yard. For any area and depth, the square feet to cubic yards converter gives the volume directly.