Compost Calculator
Calculate compost bin volume, ideal green/brown ratio, and estimated completion time from your bin dimensions.
Compost Bin Summary
Compost Bin Volume:
Volume = Length × Width × Height
Unit conversions:
- Cubic feet to cubic meters: divide by 35.315
- Cubic meters to cubic feet: multiply by 35.315
- Cubic feet to gallons: multiply by 7.48
Ideal green-to-brown ratio (by volume): 1 part green : 3 parts brown
- Greens (nitrogen-rich): grass clippings, food scraps, coffee grounds
- Browns (carbon-rich): dry leaves, cardboard, straw, wood chips
Minimum bin size for hot composting: 3 ft × 3 ft × 3 ft (27 cu ft / 0.76 cu m)
Estimated completion times:
- Hot composting (turned regularly): 4–8 weeks
- Warm composting (turned occasionally): 3–6 months
- Cold composting (passive): 6–12 months
Tips:
- Keep compost moist like a wrung-out sponge
- Turn every 1–2 weeks for faster decomposition
- Smaller pieces decompose faster