Mulch Calculator
Find out how much mulch you need for your garden beds. Enter the size of the area and how deep you want the mulch to see the cubic yards and the number of bags to buy.
Mulch needed
1.85 cu yd
Check the highlighted fields to see your result.
- Bags
- 25
- Volume
- 50 cu ft
- Area covered
- 200 sq ft
Results are estimates for information only and do not constitute financial, medical, or legal advice.
How it works
The calculator multiplies the area of the bed by the depth of mulch to get the volume. Bulk mulch is sold by the cubic yard, and bags are usually sold by the cubic foot, so you'll see both.
The formulas
Cubic feet = length (ft) × width (ft) × depth (in) ÷ 12
Cubic yards = cubic feet ÷ 27 · Bags = cubic feet ÷ bag size
Worked example
A bed is 20 ft by 10 ft and you want 3 inches of mulch, sold in 2 cu ft bags.
- Volume: 20 × 10 × 3 ÷ 12 = 50 cubic feet.
- In cubic yards: 50 ÷ 27 ≈ 1.85 cubic yards.
- Bags: 50 ÷ 2 = 25 bags.
Frequently asked questions
How deep should mulch be?
2 to 3 inches is enough for most garden beds: it keeps moisture in and weeds down. Thicker layers can keep water from reaching the soil. Keep mulch a few inches away from tree trunks and plant stems so they don't rot.
Is it cheaper to buy mulch in bags or in bulk?
For small beds, bags are easier. For larger areas, bulk mulch sold by the cubic yard is usually much cheaper. One cubic yard equals 13.5 bags of 2 cubic feet.
How much area does a cubic yard of mulch cover?
About 162 square feet at 2 inches deep, 108 square feet at 3 inches, and 81 square feet at 4 inches.