Mulch calculator
This mulch calculator tells you exactly how much mulch to buy: enter the area of your beds and how deep you want the layer, and it returns cubic yards plus bag counts.
Measure length × width in feet
Mulch calculator FAQ
How much mulch do I need?
Multiply area in square feet by depth in inches divided by 12, then divide by 27. A 100 sq ft bed at 3 inches deep needs about 0.93 cubic yards.
How deep should mulch be?
2–3 inches is the standard recommendation — deep enough to suppress weeds, shallow enough to let water through.
Bags or bulk mulch — which is cheaper?
Bags suit small beds; bulk (sold by the cubic yard) is usually cheaper per unit for large areas. This mulch calculator gives you both numbers so you can compare.
How do I measure an irregular bed?
Break it into rectangles, compute each area, and add them up — then enter the total square footage.
How often should I re-mulch?
Most beds need a fresh 1–2 inch top-up once a year as the old layer decomposes.