Mulch Calculator
Cubic yards or bags of mulch for a bed, from its area and depth.
- Volume (cubic feet)25.0
- Volume (cubic yards)0.93
- 2 cu ft bags13
Inputs used
- Bed length10 ft
- Bed width10 ft
- Mulch depth3 in
About this calculator
Mulch volume is bed area times depth: a 10 × 10 ft bed at 3 inches deep needs 25 cubic feet, just under one cubic yard. Bulk mulch sells by the cubic yard (27 cubic feet); bagged mulch most commonly comes in 2-cubic-foot bags.
Three inches is the sweet spot for most beds — enough to suppress weeds and hold moisture, not so deep that it suffocates roots. Keep mulch a few inches back from trunks and stems; the "mulch volcano" against a tree trunk invites rot.
For irregular beds, estimate the area as rectangles and circles and add them up. Bulk delivery beats bags on price above roughly a yard and a half — one cubic yard equals about 13.5 bags.
Quick reference
Cubic yards of mulch by bed size — 3 inch depth
Mulch volume in cubic yards at a 3-inch depth, by bed length and width in feet.
| Bed length | 5 ft | 8 ft | 10 ft | 12 ft | 15 ft |
|---|---|---|---|---|---|
| 5 ft | 0.23 | 0.37 | 0.46 | 0.56 | 0.69 |
| 8 ft | 0.37 | 0.59 | 0.74 | 0.89 | 1.11 |
| 10 ft | 0.46 | 0.74 | 0.93 | 1.11 | 1.39 |
| 12 ft | 0.56 | 0.89 | 1.11 | 1.33 | 1.67 |
| 15 ft | 0.69 | 1.11 | 1.39 | 1.67 | 2.08 |
| 20 ft | 0.93 | 1.48 | 1.85 | 2.22 | 2.78 |
Bags of mulch by bed length and depth — 10 ft wide
Number of 2 cu ft bags for a 10 ft wide bed, by length and mulch depth.
| Bed length | 2 in | 3 in | 4 in |
|---|---|---|---|
| 5 ft | 5 | 7 | 9 |
| 8 ft | 7 | 10 | 14 |
| 10 ft | 9 | 13 | 17 |
| 12 ft | 10 | 15 | 20 |
| 15 ft | 13 | 19 | 25 |
| 20 ft | 17 | 25 | 34 |
Frequently asked questions
How much mulch do I need for a 10x10 bed?
At the recommended 3-inch depth, a 10 × 10 ft bed needs 25 cubic feet of mulch — just under one cubic yard (0.93), or about 13 of the standard 2-cubic-foot bags.
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet, so at 2 cubic feet per bag it's about 13.5 bags. Once you need more than a yard and a half, bulk delivery is usually cheaper than bagged mulch.
How deep should mulch be?
Three inches suits most beds — enough to suppress weeds and hold moisture without smothering roots. Keep it pulled back a few inches from trunks and stems to avoid rot.
How do I measure mulch for an irregular bed?
Break the bed into rectangles and circles, work out each area, and add them together before choosing a depth. Overestimating slightly is safe since mulch settles and thins over the season.
Embed this calculator on your site
Paste this HTML where you want the calculator to appear. It stays free, works on any site, and updates automatically. Adjust the height to taste.
Results are informational only — not financial, medical or legal advice.