How to estimate mulch for garden beds

Area × depth gives volume; convert to cubic yards and round up.

Mulch is sold by volume, but you measure beds by area. The bridge is depth: a thin top-up needs far less than a fresh 3-inch layer.

This guide helps you measure beds quickly and choose a realistic depth for your goals.

Step-by-step: mulch math

  1. Measure bed area (rectangles, circles, or break irregular beds into shapes).
  2. Choose a target depth (often 2–3 inches for many beds).
  3. Convert area × depth to volume (cubic feet or cubic meters).
  4. Convert volume to cubic yards if that’s how your supplier sells mulch.
  5. Round up and consider extra if the bed has dips, slopes, or you’re topping up unevenly.

Practical tips

  • Depth matters more than people expect—double the depth doubles the volume.
  • Fresh mulch settles; add a little buffer.
  • Avoid piling mulch against tree trunks (“mulch volcano”).
  • If you’re re-mulching, measure how much old mulch you’ll remove or level first.
Want the quick yardage estimate?
Use our mulch calculator and share a link that keeps your inputs.
Use the calculator

FAQ

How deep should mulch be?
Many beds use 2–3 inches. Thin top-ups may be 1 inch; weed suppression often needs more, depending on conditions.
How many cubic yards of mulch do I need?
Compute bed area × depth to get volume, then convert to cubic yards and round up.
Should I buy extra mulch?
A small buffer helps cover settling and uneven beds, and it reduces the chance of running short mid-project.

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