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.
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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.