Compost Carbon-to-Nitrogen Ratio Calculator

Achieve the perfect balance for your compost pile! The Carbon-to-Nitrogen (C:N) ratio is crucial for efficient decomposition. Use this calculator to estimate your mix's ratio and get recommendations for a healthy, odor-free compost.

Input Your Materials

Green Materials (Nitrogen-rich)Examples: Fresh grass clippings, food scraps, coffee grounds.

Brown Materials (Carbon-rich)Examples: Dry leaves, wood chips, shredded paper, straw.

The Importance of the C:N Ratio

Composting is a natural process of decomposition carried out by microorganisms. These tiny workers need a balanced diet of carbon (energy) and nitrogen (protein) to thrive and efficiently break down organic matter. The Carbon-to-Nitrogen (C:N) ratio is a measure of the amount of carbon relative to nitrogen in your compost materials.

Why Balance Matters:

Too Much Nitrogen (Greens): Leads to a dense, slimy, and often smelly pile (ammonia odor) because the microorganisms have too much nitrogen and not enough carbon to process it.
Too Much Carbon (Browns): Results in a dry, slow-to-decompose pile because the microorganisms lack sufficient nitrogen to multiply and break down the carbon effectively.
Ideal Ratio (25-35:1): Provides the perfect food source for microorganisms, leading to rapid decomposition, heat generation, and a sweet, earthy-smelling compost.

Common Compost Materials & Their Approximate C:N Ratios:

Material	Type	C:N Ratio (approx.)	Examples
Grass Clippings	Green	19:1	Freshly cut grass
Food Scraps	Green	15:1	Fruit and vegetable peels, coffee grounds, tea bags
Manure	Green	5-25:1	Chicken, cow, horse manure
Dry Leaves	Brown	40-80:1	Fallen autumn leaves
Wood Chips	Brown	100-500:1	Sawdust, wood shavings, small branches
Shredded Paper/Cardboard	Brown	170:1	Newspaper, cardboard boxes (non-glossy)
Straw	Brown	40-100:1	Hay, dried stalks

Disclaimer: This calculator provides an estimate. Actual C:N ratios can vary based on the freshness and specific composition of materials. For best results, observe your compost pile and adjust inputs as needed.