About MulchCalc

MulchCalc is a free, browser-based mulch calculator built by gardeners who got tired of doing the same back-of-the-envelope math every spring.

Every season we'd sketch a flower bed on the back of an envelope, look up the conversion from cubic feet to cubic yards for the fourth time, then drive to Home Depot and pick the wrong bag count anyway. The math is simple — but it's simple math you do once a year, which means you forget it every winter. So we built a calculator that does it for you, without making you sit through ads, sign up, or watch a video.

The formulas are exact: area × depth = volume, with standard unit conversions. The 10% buffer for settling that we recommend is based on USDA Forest Service research on shredded hardwood mulch decomposition rates. The bag and cubic-yard conversion factors are universal (27 cu ft per cu yd is fixed by definition).

Where we're approximating: cost ranges in the cost calculator are 2026 US averages — your local supplier may be 20–30% above or below depending on region.

Every calculation runs entirely in your browser. We do not collect, store, or transmit any of the dimensions or prices you enter. We do not require an account. We do not run third-party tracking on calculator inputs. See our privacy policy for the full details.

MulchCalc is built and maintained by a small team of gardeners, landscapers, and web developers. We are not affiliated with any mulch supplier or garden retailer. If you spot a bug, a wrong conversion factor, or have a feature idea, drop us a note.

Head back to the mulch calculator, or browse the individual tools for rectangular, circular, and irregular beds.