Mulch Calculator Yards: Calculate Cubic Yards in Seconds
Whether your landscaping plans are drawn in feet, yards, or metres, use this calculator to determine the exact cubic yards of mulch needed and convert directly into UK bulk bags or litres.
How much do you need?
We round bags up so you are not caught short. Base quantity before allowance: 1,800 litres.
How to Calculate Cubic Yards of Mulch
One cubic yard of mulch represents a volume measuring 3 feet wide, 3 feet long, and 3 feet deep (3 × 3 × 3 = 27 cubic feet). When measuring garden beds in feet and inches, the universal cubic yard formula is:
Cubic Yards = (Length ft × Width ft × Depth in) ÷ 324
Divide by 324 because 27 cubic feet × 12 inches per foot = 324.
Worked Example: If your garden border is 30 feet long, 6 feet wide, and you want a standard 3-inch depth of bark:
- 30 ft × 6 ft = 180 square feet.
- 180 × 3 inches depth = 540.
- 540 ÷ 324 = 1.67 cubic yards of mulch.
- Adding 10% for settling (1.67 × 1.10) gives 1.84 cubic yards to order.
Cubic Yards to UK Litres & Bags Conversion Table
In the United Kingdom, mulch is rarely sold by the loose cubic yard unless you are collecting directly from a forestry contractor. Instead, UK suppliers sell by litres, small bags (50L–70L), or bulk bags (850L–1000L). Here is the exact conversion:
| Cubic Yards | Equivalent in Litres | Cubic Metres (m³) | UK 50L Bags | UK 70L Bags | Bulk Bags (~850L) |
|---|---|---|---|---|---|
| 0.5 cu yd | 382 L | 0.38 m³ | 8 bags | 6 bags | Half bulk bag |
| 1.0 cu yd | 765 L | 0.76 m³ | 16 bags | 11 bags | 1 bulk bag |
| 1.5 cu yd | 1,147 L | 1.15 m³ | 23 bags | 17 bags | 1.5 bulk bags |
| 2.0 cu yd | 1,530 L | 1.53 m³ | 31 bags | 22 bags | 2 bulk bags |
| 3.0 cu yd | 2,295 L | 2.30 m³ | 46 bags | 33 bags | 3 bulk bags |
| 5.0 cu yd | 3,825 L | 3.83 m³ | 77 bags | 55 bags | 4.5 bulk bags |
When to Buy in Bulk Yards vs Bags in the UK
Ordering threshold rules of thumb:
- Under 1 Cubic Yard (less than 750L): Buy individual 50L or 70L bags from retailers like B&Q, Wickes, or local garden centres. Bagged mulch is easier to transport in a car boot and carry to back gardens with narrow side-gate access.
- 1 to 4 Cubic Yards (750L to 3,000L): Order tonne bulk bags (dumpy bags). Most UK builders merchants deliver these via crane (hiab) directly onto your driveway, saving 30% to 50% compared to bagged prices.
- 5+ Cubic Yards (over 3,500L): Look into loose tipped delivery from an agricultural or landscape wholesaler. Ensure you have clear tipped truck access and lay down a tarpaulin first.