Mulch Calculator
Work out how many bags of mulch you need, or how many cubic yards to order in bulk. Rectangular and round beds, imperial or metric, instant results.
How to use the mulch calculator
- Choose the bed shape — a rectangle, or a round bed measured by its diameter.
- Enter length and width in feet, and depth in inches. Two to three inches suits most beds.
- Pick your bag size. Most bagged mulch is 2 cubic feet; some brands sell 1.5 or 3.
- Add more beds with Add another area to total a whole yard at once.
- Read bags and cubic yards together so you can compare bagged versus bulk.
Bags, cubic yards and the numbers behind them
Mulch is sold two ways: bagged (usually 2 cubic feet) and bulk by the cubic yard. The volume you need is simply bed area × depth. A cubic yard is 27 cubic feet, which equals 13.5 standard bags — a handy figure when you are deciding whether to bag it or order a load.
| Depth | Coverage per 2 cu ft bag | Coverage per cubic yard |
|---|---|---|
| 2 in | 12 sq ft | 162 sq ft |
| 3 in | 8 sq ft | 108 sq ft |
| 4 in | 6 sq ft | 81 sq ft |
Bagged or bulk?
Bags win for small refreshes and tidy hauling in a car. Bulk wins on price and on big jobs: one scoop of a loader beats opening 20 bags. The rough break-even is around 8 to 10 bags — past that, bulk usually costs less even with delivery. Have somewhere to dump a pile before you order.
Common mulch mistakes
- Piling it against trunks. Keep mulch a few inches off stems and trunks to prevent rot and pests.
- Going too deep. More than 3 to 4 inches can starve roots of air and water.
- Forgetting settling. Fresh mulch compresses; the 10 percent waste factor covers it.
Frequently asked questions
How many bags of mulch do I need?
Multiply the bed area in square feet by the depth in feet to get cubic feet, then divide by the bag size. Standard bags hold 2 cubic feet, so a 200 square foot bed at 3 inches (0.25 ft) deep is 50 cubic feet, or 25 bags. This calculator does the math and rounds up for you.
How deep should mulch be?
Two to three inches is right for most beds. Less than 2 inches lets weeds through; more than about 3 to 4 inches can suffocate roots and cause bark to rot against stems. Refresh yearly by topping up to your target depth rather than piling on a full new layer.
Is it cheaper to buy mulch in bags or in bulk?
Bulk mulch by the cubic yard is usually cheaper per unit once you need more than about 8 to 10 bags, because one cubic yard equals 13.5 standard 2-cubic-foot bags. Below that, bags are easier to haul and store. Factor in delivery fees when you compare.
How many bags are in a cubic yard of mulch?
A cubic yard is 27 cubic feet, so it equals 13.5 bags of 2 cubic feet, 9 bags of 3 cubic feet, or 18 bags of 1.5 cubic feet. Switch this tool to the volume view to see cubic yards for a bulk order.
Does mulch settle, so should I buy extra?
Yes. Fresh mulch fluffs up in the bag and settles once spread and rained on. The built-in 10 percent waste factor covers settling and the uneven edges of natural beds. Keep it on unless you are measuring a tight, edged bed.
Coverage figures are estimates for planning only. Mulch volume varies with material, moisture and how firmly it is packed. Buy a little extra rather than run short mid-bed.