Mulch Calculator

Mulch volume is area multiplied by depth, with the depth converted from inches to feet. A 10 by 10 foot bed is 100 square feet. At 3 inches deep that is 100 x 3 / 12 = 25 cubic feet. Bulk yards sell by the cubic yard, which holds 27 cubic feet, so 25 cubic feet is 0.93 cubic yards.

Bags are sold by volume, so the calculator divides cubic feet by the bag size and rounds up to whole bags. The same 25 cubic feet takes 17 bags of 1.5 cu ft, 13 bags of 2 cu ft, or 9 bags of 3 cu ft. For a circle such as a tree ring, area is pi x radius squared, so an 8 foot ring covers about 50 square feet.

• 1 cubic yard covers 324 sq ft at 1 in
• 1 cubic yard covers 162 sq ft at 2 in, 108 sq ft at 3 in, and 81 sq ft at 4 in

Bagged mulch is convenient for small jobs, but the price per cubic yard is usually two to three times higher than bulk. A 2 cu ft bag at $4 works out to about $54 per cubic yard, while bulk shredded hardwood often sells for $30 to $45 per yard before delivery. Once a job passes 2 to 3 cubic yards, bulk delivery generally wins even after a delivery fee.

Add a 5 to 10 percent allowance for uneven ground and spillage, and more for fresh wood chips, which settle noticeably in the first few weeks. A half-ton pickup bed typically holds about 2 cubic yards of loose mulch by volume.