Composting Time Calculator — How Long Until Compost Is Ready

Hot composting with regular turning can produce finished compost in 8-12 weeks. Cold composting without turning typically takes 6-12 months. Key factors are the green/brown balance, pile size, moisture, aeration, and temperature.

The ideal ratio is roughly equal volumes of greens and browns, which gives a C:N ratio of about 25-30:1. Greens (nitrogen-rich) include grass clippings, food scraps, and fresh leaves. Browns (carbon-rich) include cardboard, dry leaves, straw, and wood chips.

Finished compost is dark brown, crumbly, and smells earthy. You should not be able to identify original materials. It should be cool (no longer heating up) and reduced to about a third of the original volume.

For fastest results, turn every 2-3 days when the internal temperature drops below 55°C. Weekly turning is a good practical frequency. Even monthly turning significantly speeds up composting compared to no turning at all.

Yes. A pile of at least 1 cubic metre retains heat well enough for hot composting. Smaller piles decompose more slowly as they lose heat. Larger piles (up to 1.5m³) are even more efficient but harder to manage.