Calculate the volume of mulch needed for garden beds, paths, and landscaping areas.
This mulch calculator works out how much mulch (also called bark, bark chippings or wood chip) you need to cover a garden bed or border to a chosen depth. Enter the length, width and depth and it returns the volume in cubic yards and cubic metres, plus a rough weight and the number of bags to buy. It suits gardeners and landscapers in any country – just switch between metric and imperial units.
| Use | Depth (imperial) | Depth (metric) |
|---|---|---|
| Flower & shrub beds | 2–3 in | 50–75 mm |
| Weed suppression | 3–4 in | 75–100 mm |
| Around trees (keep off trunk) | 3 in | 75 mm |
| Play areas (wood chip) | 6 in | 150 mm |
A bed 5 m × 2 m at 75 mm deep = 10 m² × 0.075 m = 0.75 m³ (about 1 cubic yard). At roughly 400 kg per m³ that is around 300 kg, or about 10–15 standard 50–70 litre bags. One bulk (dumpy) bag typically covers this.
2-3 inches (50-75 mm) is the recommended depth for most garden beds. More can suffocate plant roots.
A standard 2 cu ft bag covers about 12 sq ft at 2 inches deep, or 8 sq ft at 3 inches deep.
Organic mulch typically needs topping up every 1-2 years as it decomposes.
Usually no — just top up the old mulch to the depth you want as it breaks down. Only remove it if it has matted, gone mouldy, or built up too thickly against plant stems and trunks.
At 50 mm deep a cubic metre covers about 20 square metres. The calculator works out volume from your area and depth.
