Planning guide
What is mulch?
Mulch is a protective layer of bark, wood fiber, leaves, or other material spread over soil. It moderates soil temperature, slows evaporation, suppresses weeds, and gives planting beds a finished appearance.
How this calculation works
Multiply the bed length by its width to find area, then multiply by the chosen depth. The calculator converts all measurements to a common base before reporting cubic feet, cubic yards, and cubic meters.
Choose an input for your project
Check the existing layer before choosing how much new mulch to add.
| Project | Depth to consider | Input check |
|---|---|---|
| Refresh | 1–2 in | Subtract mulch that remains usable |
| Established bed | 2–3 in total | Measure the finished total layer |
| New bare bed | 3–4 in | Consider mulch texture and settling |
These are planning ranges; plants, mulch texture, drainage, and existing conditions can change the appropriate depth.
Common measurement mistakes
- Using inches as feet without converting
- Measuring the entire property instead of planted bed area
- Forgetting to subtract large patios, rocks, or structures
Planning tips
- Two to three inches suits many ornamental beds
- Keep mulch away from tree trunks and plant crowns
- Rake old compacted mulch before adding a fresh layer
Mulch Calculator FAQs
How much extra mulch should I buy?
A 10% material allowance is a practical starting point for curved beds, settling, spillage, and small measurement differences. Highly irregular beds may need more.
What mulch depth should I use?
For established beds, 2–3 inches (5–8 cm) is common. New areas may need 3–4 inches (8–10 cm), while fine mulch should generally be applied more shallowly.
Should mulch touch tree trunks or plant stems?
No. Keep mulch a few inches away from trunks and crowns so moisture is not held directly against living tissue.