Example: a 20 × 4 ft flower bed, 3 in deep
- Area: 20 × 4 = 80 sq ft.
- Depth in feet: 3 in ÷ 12 = 0.25 ft. Volume: 80 × 0.25 = 20 cu ft.
- Add 5% for settling: 21 cu ft, or 0.78 cu yd (21 ÷ 27).
- Bags: 21 ÷ 2 cu ft = 10.5, so buy 11 bags of 2 cu ft (or 7 bags of 3 cu ft).
How it's calculated
- Area of the bed: length × width for rectangles, π × (diameter ÷ 2)² for circles — or enter a total area.
- Volume = area × depth, with the depth converted to feet (inches ÷ 12) or meters.
- Cubic feet ÷ 27 = cubic yards.
- Bags = volume ÷ bag size, rounded up. Bulk orders are rounded up to the next ¼ cu yd.
Assumptions
- Bag sizes: 2 and 3 cu ft (US) or 50 and 100 L.
- 5% extra by default for settling and spillage.
- Bags are suggested first up to 2 cu yd (27 bags of 2 cu ft); above that, bulk delivery usually costs less.
Frequently asked questions
How many bags of mulch are in a yard?
13.5 bags of 2 cu ft, or 9 bags of 3 cu ft. A cubic yard is 27 cubic feet.
How deep should mulch be?
2–3 inches in flower beds and around shrubs, up to 3–4 inches where you're fighting weeds. Keep mulch a few inches away from stems and tree trunks — mulch piled against bark holds moisture and invites rot.
How much area does a bag of mulch cover?
A 2 cu ft bag covers about 12 sq ft at 2 in deep, 8 sq ft at 3 in, or 6 sq ft at 4 in.
How much area does a cubic yard of mulch cover?
About 162 sq ft at 2 in deep, 108 sq ft at 3 in and 81 sq ft at 4 in.
Is bagged or bulk mulch cheaper?
Bags are handy for a few beds. Once you need more than 2–3 cubic yards, bulk mulch from a landscape supplier is usually much cheaper per yard, even after a delivery fee.
How much mulch do I need to top up an existing bed?
Only the difference. If there's still an inch of old mulch and you want 3 inches, enter a depth of 2 inches.