Compost Bin Volume and Browns Greens Ratio Calculator

Calculate the Real Capacity of a Compost Bin

A compost bin volume calculator is most useful when it works from the inside measurements, not the label on the product. Enter the width, depth, and height of a rectangular bin, or the diameter and height of a cylindrical one. The result shows the internal capacity in liters or gallons and compares it with the material volume you plan to add.

Compost Bin Volume Formulas

For a rectangular bin, use width × depth × height. If the measurements are in centimeters, divide the cubic centimeter result by 1,000 to get liters. For a cylindrical bin, use π × radius² × height, where radius is half the inside diameter. Measure the clear space inside the bin and do not count thick walls, legs, or a lid.

• Rectangular: width × depth × height.
• Cylindrical: π × radius² × height.
• Liters: 1,000 cubic centimeters.
• Fill level: brown volume plus green volume compared with internal capacity.

How Much Browns and Greens to Add

Use two to three parts browns for each part greens by volume as a practical starting point. Browns include dry leaves, shredded cardboard, and small woody material. Greens include food scraps, fresh grass, and other nitrogen rich material. The calculator reports the target brown range, but the pile itself supplies the final feedback through moisture, smell, heat, and airflow.

Read the Moisture and Air Warnings

A pile that feels dry may decompose slowly, while a saturated pile can lose air spaces and develop unpleasant odors. Aim for a wrung out sponge feel. If the pile is wet, add dry bulky browns and turn it. If it is dry, moisten it gradually while turning so the water spreads through the material.