Mulch Calculator
Convert bed area and depth into cubic feet, cubic yards, and the number of 2 or 3 cubic foot bags to buy. Everything runs in your browser.
How to use
- Measure the bed's length and width in feet and multiply them for the area. For odd shapes, break the bed into rectangles and add them, or pace it off roughly; mulch forgives.
- Enter the depth in inches. Two inches suits established beds, three to four inches is the usual range for new beds and weed suppression.
- Read the results: cubic feet and cubic yards, plus bag counts at both common bag sizes.
- Pick bags for small beds and bulk delivery by the cubic yard for big ones. Keep a couple of spare bags on hand, roughly 10 percent more than the count, for thin spots.
How the math works
Volume is area times depth: the bed area in square feet times the depth in inches divided by 12 gives cubic feet, and dividing by 27 gives cubic yards. Bag counts divide the cubic feet by 2 or by 3 and round up, because bags sell whole. Results are rounded to two decimals.
The math assumes a level bed with a uniform depth. Slopes, mounds, and islands of different depths need their own line each.
Estimates are estimates. Buy about 10 percent more mulch than the count, or keep a spare bag or two, for thin coverage at the edges.
Frequently asked questions
Is anything I enter uploaded or stored?
No. The calculator runs entirely in your browser tab, and your numbers never leave the page. Nothing is stored, nothing is sent to a server, and the page sets no cookies. Ad slots on the page are served by third-party networks, which follow their own privacy policies.
How deep should mulch be?
Two to four inches is the standard range for beds: enough to hold moisture and shade out weeds, not so much that roots suffocate. Fine bark sits closer to two inches, coarse chips closer to four. Piling mulch against trunks and stems causes rot, so keep a gap around them no matter what depth you choose.
Bags or bulk delivery?
Roughly 13 to 14 of the 2 cubic foot bags make one cubic yard. Past about a yard and a half, bulk delivery usually wins on price and on your back, and you avoid a driveway full of empty bags. The result shows both so you can price each way.
Does the calculation account for settling?
No, it is the volume of the finished layer. Fresh mulch settles and breaks down over a season, so a bed topped up last spring often needs only an inch or two this year rather than the full depth again.