Loading page
About this tool
Size a home compost bin in litres from daily kitchen waste, browns ratio and how often you turn the heap.
A compost bin is sized by the volume of material sitting in it at any moment, not by the weight of scraps you throw in each day — and this calculator converts one into the other. It takes your daily wet kitchen waste at a bulk density of about 0.5 kg per litre, adds the dry browns needed to reach the 25–30:1 carbon-to-nitrogen ratio aerobic composting requires, holds that charge for the retention period your turning regime implies, and averages the fresh and shrunken volumes before adding 25% headspace for turning.
Open Compost Bin Size Calculator on AltFTool — it loads instantly in your browser.
Enter the values you already know.
Fine-tune the options to match your scenario.
Read the result and use it in your planning or reporting.
Converts kilograms of scraps into the litres a bin actually has to hold, including the browns you mix in.
A cold heap holds material for five months and needs two to three times the volume of a turned hot bin at the same daily input.
Reports the cube side in centimetres per chamber, so you can lay out a masonry bay or check a product listing.
Roughly 200–250 litres of total system volume for about 1 kg of kitchen waste a day on a 60-day turned cycle — commonly sold as a three-pot set of 60–80 litres each. A family of two producing around 0.5 kg a day needs about half that.
By volume, roughly two parts dry leaves, one and a half parts shredded cardboard, or one part cocopeat per one part wet kitchen waste. The target is a carbon-to-nitrogen ratio of 25–30:1; kitchen scraps sit near 15–20:1 on their own, which is why a nitrogen-only heap turns slimy and smells.
About 45–60 days in a tumbler or hot bin turned every three to four days, 90 days if you turn weekly, and four to six months for a static cold heap. Longer cycles need proportionally more bin volume because material sits in the system longer.
Around 20–30% of the wet weight you put in, because kitchen waste is 70–80% water and further carbon leaves as carbon dioxide. One kilogram of scraps a day for a year — 365 kg — yields roughly 90 kg of finished compost.
Add the Compost Bin Size Calculatorwidget to your blog or website — free, responsive, no signup. Just keep the “Widget by AltFTool” credit link visible.
<iframe src="https://www.altftool.com/embed/widget/compost-bin-size-calculator"
title="Compost Bin Size Calculator — free AltFTool widget"
width="100%" height="640" style="border:0;border-radius:12px;overflow:hidden"
loading="lazy" referrerpolicy="no-referrer-when-downgrade"></iframe>
<p style="font-size:12px;margin:4px 0 0">Widget by <a href="https://www.altftool.com/tools/all/compost-bin-size-calculator?utm_source=embed&utm_medium=widget">AltFTool — free online tools</a></p>