Mulch Calculator
Mulch is sold two ways: in 2-cubic-foot bags from the garden center or by the cubic yard from a bulk supplier. The trick is knowing which is cheaper for your job, and that comes down to how much you actually need. Enter your bed dimensions and the depth you want below. You'll get bags, cubic yards, and a cost estimate, so you can see at a glance whether to grab bags or order a bulk drop.
How this is calculated
Multiply the bed's length by its width to get square footage, then multiply by depth in feet (your inches divided by 12) for cubic feet. One standard bag holds 2 cubic feet, so bags equal cubic feet divided by 2. For bulk, divide cubic feet by 27 to get cubic yards. A 2 to 3 inch layer is right for most beds; go thinner around shallow-rooted plants.
A worked example
A 20 by 10 foot bed at 3 inches deep is 200 square feet times 0.25 feet, or 50 cubic feet. That's 25 bags, or just under 2 cubic yards. Once you're past about 12 bags, a bulk yard usually beats bagged on price, which is exactly the call this tool helps you make.
Common questions
Measure your bed's length and width, pick a depth of 2 to 3 inches for most plantings, and the calculator converts that into bags and cubic yards. A rough rule: one cubic yard covers about 100 square feet at 3 inches deep.
Thirteen and a half. A cubic yard is 27 cubic feet and each bag holds 2, so 27 divided by 2 is 13.5 bags per yard. That's why bulk gets cheaper fast on bigger jobs.
Two to three inches for established beds. Too thin and weeds push through; too thick and you can suffocate roots and trap moisture against stems.
Bulk almost always wins per cubic foot, but you pay for delivery and you have to move it yourself. For small beds under a dozen bags, bagged is simpler. The cost estimate above lets you compare both for your size.
Estimates for planning. Verify against your supplier's units and your local building codes before ordering or building. For anything structural, follow your engineer or local code.