Mulch calculator

How it works

Mulch is sold by volume, so the calculator turns your bed into a box. Multiply length by width to get square feet, then multiply by depth in feet (inches ÷ 12) to get cubic feet. One cubic yard is 27 cubic feet, so divide by 27 for a bulk order. For bags, divide cubic feet by the bag size and round up.

For a curved or odd-shaped bed, split it into rough rectangles, run each one, and add the results. Being a little generous is fine. Leftover mulch keeps.

Example

With bed length 20 ft, bed width 10 ft, mulch depth 3 in, bag size: 2 cu ft bag, the answer is 1.85 cubic yards.

Tips before you buy

• Keep mulch a few inches away from tree trunks and plant stems. Piling it against bark holds moisture against the trunk.
• Topping up last year’s mulch usually takes only an inch or so. Measure what’s already there before you order a full depth.
• Bulk mulch is priced per cubic yard. Multiply your bag count by the bag price and compare. Past a couple of yards, delivery often wins.
• A cubic yard of mulch fills a standard wheelbarrow roughly 9 to 14 times, depending on the wheelbarrow.

Common questions

How many bags of mulch are in a cubic yard?

A cubic yard is 27 cubic feet. That works out to 13.5 bags of 2 cu ft, 9 bags of 3 cu ft, or 18 bags of 1.5 cu ft.

How much area does a cubic yard of mulch cover?

At 3 inches deep, one cubic yard covers about 108 square feet. At 2 inches it covers about 162 square feet.

How deep should mulch be?

Most beds do well with 2 to 3 inches. Thinner layers let weeds through, and much more than 4 inches can keep water and air from reaching the soil.