Compost ratio calculator

Stop the smell and speed up the rot. Balance your Carbon (Browns) and Nitrogen (Greens) for a perfect compost pile.

Grass, kitchen scraps, manure
Leaves, straw, cardboard, woodchips

Measured by volume (e.g. buckets or wheelbarrows).

Approx. C:N Ratio
30:1
Perfect Balance

The "Rotten Egg" warning

I genuinely don't know why people make composting sound like a hobby for scientists. It’s actually very simple: if your pile smells like ammonia or rotten eggs, you’ve got too many "Greens" (Nitrogen). If absolutely nothing is happening and the pile is cold, you’ve got too many "Browns" (Carbon).

The "Golden Rule" is a 30:1 ratio of Carbon to Nitrogen. This doesn't mean 30 buckets of leaves to 1 bucket of scraps—because leaves themselves have some nitrogen. A safe, easy volume ratio for most backyard bins is 3 parts Brown to 1 part Green. If you stick to that, your pile will be hot, hungry, and smell like fresh earth.

What is what?

  • Greens (High Nitrogen): Vegetable scraps, coffee grounds (yes, they are green!), fresh grass clippings, chicken manure.
  • Browns (High Carbon): Dried leaves, shredded cardboard, straw, saw dust, wood chips.