Compost Pile C:N Ratio Calculator
Enter the weight of your 'green' (nitrogen-rich) and 'brown' (carbon-rich) compost materials along with their typical C:N ratios to calculate your pile's overall balance.
About this calculator
Calculate the carbon-to-nitrogen (C:N) ratio of your compost pile from the weights of different green and brown materials to check if it's balanced.
Frequently Asked Questions
What's the ideal C:N ratio for compost?
Most compost piles decompose fastest at a C:N ratio between 25:1 and 30:1. Too much nitrogen (low ratio) can smell; too much carbon (high ratio) slows decomposition.
What are typical green and brown materials?
Greens include grass clippings, food scraps, and coffee grounds (low C:N ratio, roughly 15-20:1). Browns include dry leaves, straw, and cardboard (high C:N ratio, roughly 40-80:1).
How is the overall ratio calculated?
Each material's weight is split into estimated carbon and nitrogen mass based on its known C:N ratio, then all carbon and nitrogen totals are combined and divided.