Compost Ratio Calculator
The one number that makes compost work. Enter what you are adding and see if your heap is balanced.
A healthy compost heap wants roughly equal parts greens (wet, nitrogen-rich: food scraps, fresh grass, manure) and browns (dry, carbon-rich: dead leaves, cardboard, straw) by volume. Too many greens and it turns to smelly slop, too many browns and it just sits there. Count your buckets and check the balance.
Quick reference
- Greens: food scraps, fresh grass clippings, green leaves, coffee grounds, manure, weeds without seeds.
- Browns: dry leaves, cardboard, newspaper, straw, sawdust, dry stalks.
- Aim: roughly equal parts by volume. When in doubt add more browns, since most heaps fail from too many greens.
Frequently Asked Questions
What is the right ratio of greens to browns in compost?
Roughly equal parts by volume is the simple target. If in doubt, lean towards more browns, since most backyard heaps fail from too many greens, which turns them slimy and smelly.
What counts as a green and what counts as a brown?
Greens are wet and nitrogen-rich: food scraps, fresh grass, coffee grounds and manure. Browns are dry and carbon-rich: dead leaves, cardboard, straw and sawdust. The calculator balances the two by the bucket.
My compost is slimy and smells, what is wrong?
Too many greens and not enough air. Add browns like dry leaves or torn cardboard and turn the heap. The calculator shows how many buckets of browns to add to bring it back into balance.