How Do I Calculate How Much Mulch I Need?
Multiply length × width × depth (in inches), divide by 12 to convert to feet, then divide by 27 for cubic yards. One cubic yard covers about 108 square feet at 3 inches deep. A standard 2-cubic-foot bag covers roughly 8 square feet at 3 inches. Enter your dimensions above for exact bag counts.
Mulch is measured in cubic yards for bulk orders or by the bag for smaller projects. One cubic yard of mulch covers about 108 square feet at 3 inches deep, or 162 square feet at 2 inches deep.
Formula: Length (ft) × Width (ft) × Depth (in) ÷ 12 ÷ 27 = Cubic Yards. A standard 2-cubic-foot bag covers about 8 square feet at 3 inches deep.
How Deep Should Mulch Be?
Most garden beds need 2–3 inches of mulch; tree rings need 3–4 inches kept 6 inches from the trunk. Playground areas require 6–12 inches of rubber mulch for fall-height safety. Too much mulch suffocates roots; too little lets weeds through.
- Garden beds: 2-3 inches
- Tree rings: 3-4 inches (keep 6" from trunk)
- Walkway borders: 2-3 inches
- Playground areas: 6-12 inches (rubber mulch for safety)
- Slope erosion control: 3-4 inches
Is Bulk or Bagged Mulch Cheaper?
Bulk mulch is 2–3× cheaper per cubic yard. Bulk runs $20–45 per yard delivered, while bagged mulch costs $40–95 per yard equivalent. For anything over 3 cubic yards, bulk delivery saves significant money and time.
How Often Should I Replace Mulch?
Replace organic mulch every 1–2 years; cedar lasts 2–3 years. Hardwood, cedar, and pine bark decompose and should be topped off annually. Rubber mulch doesn’t decompose but costs 3–5× more upfront.
Related Calculators
- Topsoil Calculator— Estimate topsoil for lawns and garden beds
- Sand Calculator— Calculate sand for play areas and fill
Written by Daniel McCarney — AceCalc