Compost Ratio
Calculator
Results
- Carbon nitrogen ratio
- 45
Home and garden results
| Carbon nitrogen ratio | 45 |
formula-map diagram
- Carbon nitrogen ratio
- 45
Home and garden relationship
Formula
C:N = (Cb × Rb + Cg × Rg) ÷ (Cb + Cg)= 45
Note
This result uses the values you entered and a simplified planning equation; verify quantities and local requirements before purchasing or building.
More in Home and garden
See all →Frequently asked questions
What do "greens" and "browns" mean in a compost ratio?+
Greens are nitrogen-rich materials like fresh grass clippings, vegetable scraps, and coffee grounds, while browns are carbon-rich materials like dry leaves, straw, and cardboard. The classic target ratio is about 2-3 parts browns to 1 part greens by volume.
What happens if my compost has too many greens and not enough browns?+
Excess greens make the pile too wet and nitrogen-heavy, which leads to a slimy texture and a strong ammonia smell as it decomposes anaerobically. Adding more dry browns and turning the pile usually fixes it within a week or two.
Why is the ratio measured by volume rather than weight?+
Volume is what you're actually layering into the bin, and it correlates well enough with the carbon-to-nitrogen balance that matters for decomposition, whereas weighing ingredients each time would make composting impractical for most home gardeners.
My compost isn't heating up — is the ratio the problem?+
It's the most common cause. A pile with too many browns and too few greens lacks the nitrogen microbes need to multiply and generate heat, so adding fresh greens and moisture, then turning the pile, typically restarts active decomposition.
Does the brown-to-green ratio change with the season?+
Not the target ratio itself, but the mix of materials available does — fall gives you abundant dry leaves (browns) with fewer greens, so many gardeners stockpile leaves to add gradually through the following seasons when fresh green material is more abundant.