Compost Ratio Calculator

• Compost ratio calculator to help you calculate the carbon-to-nitrogen ratio (C:N) of compost materials
• Supports common composting materials like dried leaves, straw, cardboard, grass clippings, kitchen scraps and coffee grounds
• Shows in real time whether the C:N ratio is within the ideal range (25:1–30:1)

1. Open the tool page — no download or installation needed
2. Enter the amount of each material under the Brown (high-carbon) and Green (high-nitrogen) sections
3. Results update live as you type; click Reset to restore the default mix

• This tool is completely free and requires no sign-up
• All calculations run locally in your browser — your data never leaves your device

Free online compost ratio calculator to help you calculate the carbon-to-nitrogen ratio (C:N) of compost materials. Supports common composting materials like dried leaves, straw, cardboard, grass clippings, kitchen scraps, coffee grounds, and more. Shows real-time whether the C:N ratio is in the ideal range.

Open the tool page — no download or installation needed Enter the amount of each material under the Brown (high-carbon) and Green (high-nitrogen) sections Results update live as you type; click Reset to restore the default mix

This tool is completely free and requires no sign-up All calculations run locally in your browser — your data never leaves your device

Yes, Compost Ratio Calculator is completely free. No download or installation required — it runs right in your browser.