Balance a compost pile: find its carbon-to-nitrogen ratio from your greens and browns, and how much brown material brings it to 30:1.
Result
How to use this tool
Weigh nitrogen-rich material such as food scraps and fresh grass.
Weigh carbon-rich material such as dry leaves and straw.
Aim for roughly 25–30:1 for active composting.
Use the extra-browns figure to correct a nitrogen-rich pile.
Formula & worked example
10 lb of 20:1 greens mixed with 10 lb of 60:1 browns gives a 30:1 pile — the classic composting target.
Limitations — read this before you rely on it
Uses published average C:N values and assumes similar carbon content per pound. Moisture, particle size and material type shift real composting behaviour.
Frequently asked questions
Greens are moist, nitrogen-rich materials; browns are dry, carbon-rich materials. Colour is only a rough guide.
About 25–30:1 is the usual target for fast, hot composting.
Excess nitrogen smells of ammonia; add browns and turn the pile.
Too much carbon slows breakdown; add greens or manure and water.
No. Rough proportions work fine — the ratio is a guide, not a laboratory measurement.