Compost Ratio Table: Browns needed by Greens (nitrogen) volume
Reference table of browns needed for Compost Ratio across a range of greens (nitrogen) volume values — exact, engine-computed figures you can read off at a glance.
Compost Ratio Calculator
Verified formula Updated Jun 2026 Private — runs on your device
Verified formula
Private
Browns needed
30.0
- Total compost volume
- 40.0
For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.
How to use the Compost Ratio Calculator
The Compost Ratio Calculator works out your browns needed, along with 1 related figure in an instant. Enter greens (nitrogen) volume and browns : greens ratio and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.
- Enter the greens (nitrogen) volume.
- Enter the browns : greens ratio.
- Read off your browns needed, together with total compost volume — the calculator updates automatically, with no button to press.
Formula
The Compost Ratio Calculator uses the formula:
Browns needed = Greens (nitrogen) volume × Browns : greens ratio
Worked example
For example, with greens (nitrogen) volume of 10 litres and browns : greens ratio of 3, the browns needed is 30.0.
| Greens (nitrogen) volume | 10 litres |
|---|---|
| Browns : greens ratio | 3 |
| Browns needed | 30.0 |
|---|---|
| Total compost volume | 40.0 |
Results are estimates for educational use, not professional advice.
Key terms explained
- Volume
- The amount of three-dimensional space an object occupies, measured in cubic units.
- Ratio
- A comparison of two quantities showing how many times one contains the other.
Frequently asked questions
By volume, about 3 parts browns to 1 part greens works well. For 10 litres of greens, add 30 litres of browns.
Browns are dry, carbon-rich materials like leaves and cardboard; greens are moist, nitrogen-rich materials like food scraps and grass.
Too many greens make the pile wet and smelly. Add more browns to restore balance and airflow.
A good balance of carbon and nitrogen, plus moisture and turning, helps microbes break material down faster.
The Compost Ratio Calculator uses the formula: Browns needed = Greens (nitrogen) volume × Browns : greens ratio. For example, with greens (nitrogen) volume of 10 litres and browns : greens ratio of 3, the browns needed is 30.0.
Enter the greens (nitrogen) volume. Enter the browns : greens ratio. Read off your browns needed, together with total compost volume — the calculator updates automatically, with no button to press.
Related guides
How to Calculate Compost Ratio: Formula, Steps & Examples
Learn how to calculate Compost Ratio — the formula explained step by step, with worked examples and a free calculator to check your answer.