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Compost Ratio Calculator

Green:brown ratio for a healthy pile. Pile health tier, what to add, do-not-add list.

Updated April 2026
Current ratio (green:brown)
1:2.0
Target: 1:3 by volume (≈30:1 C:N by mass)
Pile health
balanced
Ratio is within the healthy 1:2 to 1:4 range. Turn weekly and keep moisture like a wrung-out sponge.
Green (nitrogen)
  • Grass clippings (fresh)
  • Fruit & vegetable scraps
  • Coffee grounds & filters
  • Tea bags
  • Eggshells (crushed)
  • Fresh garden trimmings
  • Manure (herbivore only)
  • Seaweed
Brown (carbon)
  • Dry fall leaves
  • Shredded cardboard
  • Straw & hay
  • Sawdust (untreated)
  • Pine needles
  • Wood chips
  • Shredded newspaper
  • Dryer lint (natural fibers)
Do not add
  • Meat, fish, bones
  • Dairy products
  • Oils & fats
  • Diseased plants
  • Pet waste (dog/cat)
  • Treated wood or sawdust
  • Coal/charcoal ash
  • Weeds with mature seeds
How it works: Compost microbes need a carbon-to-nitrogen balance around 30:1 by mass, which translates to roughly 1:3 greens-to-browns by volume since browns are bulkier. Too much green → slimy, ammonia smell. Too much brown → pile won’t heat up.
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What it does

Pile too wet and smelly? Too dry and inactive? Target 1:3 green:brown. This shows your current balance and what to add.

Runs entirely in your browser — no upload, no account, no watermark. For more tools in this category see the full tools index.

Embed this tool on your siteShow snippet

Paste this snippet into any page. Loads on-demand (lazy), no tracking scripts, and sized to most dashboards. Replace the height to fit your layout.

<iframe src="https://freetoolarena.com/embed/compost-ratio-calculator" width="100%" height="720" frameborder="0" loading="lazy" title="Compost Ratio Calculator" style="border:1px solid #e2e8f0;border-radius:12px;max-width:720px;"></iframe>
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How to use it

  1. Enter green + brown volumes.
  2. Read ratio + health tier.
  3. Adjust to balance.

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