About this calculator
How much mulch or bark you need for beds and borders, in cubic metres for bulk delivery and 25 or 50 litre bags.
How it’s calculated
Volume = area × depth. 1 m³ = 1,000 litres = 20 bags of 50 L.
Worked example
With these inputs:
- Area shape
- Rectangle
- Length
- 6 m
- Width
- 3 m
- Depth
- 75 mm
- Material
- Hardwood chip mulch
- Extra allowance
- 0%
the result is:
- Volume
- 1.35 m³
- Area
- 18 m²
- Approx. weight
- 540 kg
- 25 L bags
- 54 bags
- 50 L bags
- 27 bags
Tips from the trade
- 75–100 mm is the usual depth for weed suppression and to hold moisture through summer.
- Keep mulch a hand’s width clear of trunks and stems.
- Bulk works out cheaper than bags above about 1 m³.
Common questions
How many bags of mulch in a cubic metre?
20 bags of 50 L, or 40 bags of 25 L.
Results are estimates for planning and pricing. Check quantities against your drawings, the manufacturer’s data and the NCC and Australian Standards before ordering.