Compost Ratio Calculator
Balance greens and browns for fast compost.
Enter your values
Results update instantly as you type — no submit needed.
Results
- Current C:N ratio
- 45:1
- Verdict
- Too much brown — add greens
- Browns for target
- 10 kg
- Total pile mass
- 60 kg
Quick answer
Compost breaks down fastest at a carbon to nitrogen ratio near 30:1.
C:N = Σ(mass × C:N) ÷ Σmass
How to use the Compost Ratio Calculator
- 1Weigh your greens and browns.
- 2Use typical C:N values or look up your materials.
- 3Adjust until the ratio sits near 30:1.
Frequently asked questions
What counts as greens?
Grass clippings, food scraps and manure.
Why does my pile smell?
Too many greens and not enough air — add browns and turn it.