Mulch Calculator
Estimate how much mulch you need for a garden bed or landscaped area. Enter the area size and the depth you want to spread.
| Area shape | |
| Length | |
| Width | |
| Depth | |
| Bag size |
Mulch needed
Your estimate will appear here.
Formulas
- Volume = area × depth. (Rectangle: length × width; Circle: π × (diameter/2)².)
- 1 cubic yard = 27 cubic feet. 1 cubic foot = 1,728 cubic inches.
- Number of bags = total volume (cu ft) ÷ bag size, rounded up so you have enough.
A common mulch depth is 2–4 inches. Uneven ground, settling, and compaction can change how much you need — it’s usually fine to round up a little.
How it works
Mulch volume equals the area you cover times the depth.
Formula
- Volume = area × depth (consistent units). 1 yd³ = 27 ft³; common bags are 2 or 3 ft³.
Worked example
10×10 ft at 3 in deep: 25 ft³ ≈ 0.93 yd³ (~13 bags of 2 ft³).
Estimate only. Actual needs vary by settling, depth, and product. Confirm with your supplier if needed.
How to use the Mulch Calculator
It takes a few seconds, and every figure is calculated in your browser.
- Pick the shape of the area.
- Enter the length.
- Enter the width.
- Enter the depth.
- Enter the bag size.
- Press Calculate — the result appears in the dark panel beside the form.
- Use Copy, CSV, Share or Print under the result if you want to keep it.
Mulch Calculator — frequently asked questions
What formula does the Mulch Calculator use?
Volume = area × depth. (Rectangle: length × width; Circle: π × (diameter/2)².) 1 cubic yard = 27 cubic feet. 1 cubic foot = 1,728 cubic inches. Number of bags = total volume (cu ft) ÷ bag size, rounded up so you have enough. A common mulch depth is 2–4 inches. Uneven ground, settling, and compaction can change how much you need — it’s usually fine to round up a little.
How does the Mulch Calculator work?
Mulch volume equals the area you cover times the depth.
Can you walk through a worked example?
10×10 ft at 3 in deep: 25 ft³ ≈ 0.93 yd³ (~13 bags of 2 ft³).
Last updated 10 November 2026 · Formula, worked example and assumptions are documented above, and every result is calculated in your browser.