Compost C:N Ratio Calculator
Calculate the carbon to nitrogen ratio of your compost mix for optimal decomposition (ideal: 25-30:1).
Compost C:N Ratio Calculator
Calculate the carbon to nitrogen ratio of your compost mix for optimal decomposition
Add your compost materials and their relative amounts (parts/buckets/wheelbarrows)
Formula
C:N Ratio = Total Carbon / Total NitrogenOptimal range is 25:1 to 30:1
How to Use
- 1Add materials — Select the materials you're adding to your compost.
- 2Enter amounts — Input relative amounts (parts, buckets, or wheelbarrows).
- 3Calculate ratio — Click calculate to see your C:N ratio.
- 4Adjust if needed — Follow suggestions to reach the optimal 25-30:1 range.
Frequently Asked Questions
What is the ideal C:N ratio for compost?
The ideal C:N ratio is 25:1 to 30:1. This provides the right balance for microorganisms to break down materials efficiently.
What are "greens" and "browns"?
Greens are nitrogen-rich materials (grass, food scraps, manure). Browns are carbon-rich materials (leaves, straw, cardboard). You need both for good compost.
What happens if my C:N ratio is too high?
High C:N (too much carbon) slows decomposition. The pile will be dry and take longer to break down. Add more greens.
What happens if my C:N ratio is too low?
Low C:N (too much nitrogen) causes odor problems and nutrient loss. The pile may become slimy and smelly. Add more browns.
Do I need to measure exactly?
No, rough estimates work fine. The calculator helps you understand the balance. A general rule is 2-3 parts browns to 1 part greens by volume.