Sustainability
Compost C:N Ratio
Balance greens and browns for a hot pile — browns-to-greens by volume for the 25:1 to 30:1 sweet spot.
Compost C:N Ratio
Inputs
25:1–30:1 is the hot-compost sweet spot
Kitchen scraps, grass clippings, manure — ~20:1 avg C:N
Dry leaves, straw, shredded cardboard — ~80:1 avg C:N
Results
Current C:N
Too carbon-heavy — add greens to speed decomposition.
60.0 : 1
Total volume
6.0 cu ft
Greens to add
To hit your target ratio
24.00 cu ft
How to use this
Hot compost wants a carbon-to-nitrogen ratio between about 25:1 and 30:1. Too much nitrogen (kitchen scraps alone) goes anaerobic and stinks. Too much carbon (a pile of dry leaves) just sits there for a year.
Measured by volume, roughly 2–3 parts browns to 1 part greens usually lands you in the sweet spot. Water to a "wrung sponge", turn weekly, and you should see 130–160°F within a week.
Formula
C:N of mix = (greens × 20 + browns × 80) ÷ (greens + browns)
Add-browns solves: (g · 20 + (b + x) · 80) ÷ (g + b + x) = target
Add-greens solves: ((g + y) · 20 + b · 80) ÷ (g + b + y) = target
Related calculators
Formula
C:N_mix = (g·20 + b·80) / (g + b)