Compost Calculator
Bin cubic yards plus a volume split for browns and greens. Click any i for detail.
Bin
Length (ft)
i
Length
Inside length of the bin or pile footprint. |
|
|---|---|
Width (ft)
i
Width
Inside width. |
|
Height (ft)
i
Height
Working height of the pile, not the lid. |
|
Brown : green ratio
i
Ratio
Volume parts of browns per 1 part greens. 3 is a common sketch (3:1). |
How to use this calculator
- Enter inside bin dimensions.
- Set a brown:green volume ratio.
- Read cubic yards and the split.
- Raised-bed fill is a different page.
Results explained
Volume = L × W × H, then ÷ 27 for yards. Browns = yards × ratio / (ratio+1). Greens take the rest. C:N chemistry is not this geometry.
Quick reference: compost bins
A 4×4×3 ft bin is about 1.8 cubic yards.
| Item | Detail |
|---|---|
| 4×4×3 ft | 48 ft³ ≈ 1.78 yd³ |
| 3:1 sketch | Common volume starting point |
| Raised beds | Raised bed soil calculator |
| Finished compost on a lawn | Topsoil / mulch pages |
Hot piles still need air and moisture — not in the yardage.
How the estimate is built
yd³ = L×W×H / 27. browns = yd³ × r/(r+1).
Example scenario
4×4×3 ft at 3:1 → 1.78 yd³ (~1.33 browns / 0.44 greens).
FAQ
Weight?
Greens are heavier; this is volume.
Tumbler?
Use the drum’s stated cubic feet.
Kitchen scraps only?
That’s the greens side of the ratio.