Mulch Calculator
Enter your bed size to get the mulch you need in cubic yards and bags, plus an estimated cost. Waste is included.
Mulch needed
Estimated cost
How to calculate mulch
Mulch is sold by volume. For a rectangular bed, multiply length by width by depth, with everything in feet, then convert to cubic yards by dividing by 27. Depth is usually quoted in inches, so divide it by 12 first.
Formula: cubic yards = length (ft) × width (ft) × depth (in ÷ 12) × (1 + waste %) ÷ 27, and 2 cu ft bags = cubic feet ÷ 2
Worked example: 20 ft × 10 ft × 3 in bed
Volume = 20 × 10 × (3 ÷ 12) = 50 ft³. Add 10% for waste and uneven ground: 55 ft³. Divide by 27: 2.04 cubic yards. In bags, that is 28 bags of 2 cu ft mulch.
How deep should mulch be?
Garden beds are normally 2 to 3 inches. Less than 2 inches does little for weeds or moisture. More than 4 inches can suffocate roots, so do not pile mulch against tree trunks.
Bags or bulk?
One cubic yard equals 13.5 bags of 2 cu ft mulch. For beds over about 3 cubic yards, bulk delivery is usually cheaper. For small beds, bags are easier to carry and store.
Common bed sizes
Cost tips
Prices on this page are editable estimates, not quotes. Get 2 to 3 local quotes before you buy, and ask if delivery is included. Delivery, tax and waste can change the total a lot. Order a little extra for cuts and breakage, and confirm final quantities with your supplier or a qualified professional.
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Frequently asked questions
How much mulch do I need for a 20x10 bed?
A 20 ft by 10 ft bed at 3 inches deep needs about 2.04 cubic yards with 10% waste, which is 28 bags of 2 cu ft mulch.
How deep should mulch be?
2 to 3 inches for garden beds. Playgrounds need 6 to 12 inches depending on the fall height and local rules.
How many bags of mulch are in a cubic yard?
One cubic yard is 13.5 bags of 2 cu ft mulch, or 27 bags of 1 cu ft mulch.
Bags or bulk mulch, which is cheaper?
Bulk is usually cheaper per yard for large beds. Bags make sense for small beds and when you have no place to dump a pile.
Are the prices accurate?
Prices are editable estimates. The defaults are typical US figures, and your local price can be higher or lower. Delivery fees are not included.
Should I put landscape fabric under mulch?
Fabric helps with weeds but can block water and air over time. Many gardeners skip it and just top up mulch once a year.