Mulch Calculator
Calculate the volume and weight of mulch needed to cover a garden bed at a given depth.
- Free to use
- Accurate results
- No registration required
- Works on all devices
Enter your garden bed's length, width, and desired mulch depth to find the volume needed.
5-10cm is typical for a mulch layer around garden beds.
Organic mulch is much lighter than soil or gravel — 300-500 kg/m³ is typical, depending on material and moisture.
Your result
1.35
Volume
Weight (kg)540
Weight (tonnes)0.54
AI explanation
Formula
Volume = length × width × depth; weight = volume × densityWorked example
6m × 3m garden bed, 7.5cm deep
| Field | Value |
|---|---|
| Area length (m) | 6 |
| Area width (m) | 3 |
| Depth (cm) | 7.5 |
| Mulch density (kg/m³) | 400 |
| Volume | 1.35 |
| Weight (kg) | 540 |
| Weight (tonnes) | 0.54 |
Assumptions
- Organic mulch density varies widely by material (bark, wood chips, straw) and moisture content — 400 kg/m³ is a rough average; check your specific product if weight matters for delivery planning.
Frequently asked questions
How deep should mulch be applied?
5-10cm is typical around garden beds and trees — too thin doesn't suppress weeds effectively, too thick can smother plant roots.
Why is mulch so much lighter than gravel or topsoil?
Organic mulch (bark, wood chips) is a loose, low-density material compared to mineral materials like gravel or soil, so the same volume weighs much less.
Is mulch sold by volume or weight?
Almost always by volume (often in bags or bulk cubic meters/yards) rather than weight — the volume figure here is what you'll typically need for ordering.