Size your compost bin accurately for better planning. Compare shapes, units, and fill levels quickly. Export results to share with your gardening crew today.
Knowing true bin capacity helps you schedule turning, watering, and browns-to-greens balance. A 0.75 m^3 bin can hold about 450 kg of moist compost at 600 kg/m^3, so overfilling may restrict airflow. Track capacity to match your weekly kitchen scraps, yard waste, and carbon additions, and to avoid anaerobic pockets that slow decomposition.
Garden bins are rarely perfect boxes. Cylindrical leaf bins and tapered planters behave differently than square frames. This calculator supports rectangular, cylinder, frustum, and triangular prism shapes so you can model common designs. Selecting the closest geometry reduces error compared with guessing from labeled “gallon” ratings, which often assume a brim-full fill level.
Mixing inches and centimeters creates large volume errors because volume scales with the cube of length. Converting dimensions to meters internally standardizes inputs, then outputs liters, cubic feet, and US gallons for quick comparison. As a reference, 1 m^3 equals 1000 liters and about 35.315 ft^3, making it easy to sanity-check results.
Most bins run below full height due to settling and active turning space. Using an 80% fill factor on a 240 liter round bin yields 192 liters of working volume, which is more realistic for routine loading. This approach also supports seasonal planning, such as running bins lower in wet months to improve drainage and oxygen exchange.
Bulk density varies widely by material and moisture. Mulch may be near 250 kg/m^3, while damp garden soil can exceed 1200 kg/m^3. Estimating mass helps you choose wheels, lifting points, and safe carry limits. Use the custom density option when you have supplier specs or measured weights for your mix. For bagged amendments, compare estimated mass with package labels to calibrate density. Over time, exporting results to CSV builds a small log you can use to forecast material purchases and finished compost output across different seasons and feeds.
Measure internal length, width, and height where material actually sits. If walls taper, use the frustum option. For irregular bins, average several measurements and avoid including rim flare or handles.
Set Fill percentage to your typical working level, such as 70–90%. This scales the geometric volume to a practical capacity and helps plan turning space and settling over time.
Ratings may assume brim-full volume, include external dimensions, or round heavily. Using internal dimensions and a realistic fill percentage usually matches real-world usable capacity more closely.
Pick the material closest to what you store: compost, mulch, soil, potting mix, or water. If your mix is unusual, use Custom and enter a measured or supplier-provided kg/m^3 value.
Yes. Convert your result to liters and divide by the bag’s liters, or convert to cubic feet and divide by the bag’s cubic feet. Remember to apply a fill percentage for working space.
Treat it as an approximation. Moisture content, compaction, and debris change density significantly. When in doubt, measure a known container, calculate its volume, and back-calculate density for better accuracy.
| Example | Shape | Dimensions | Fill % | Result (approx.) |
|---|---|---|---|---|
| Backyard compost box | Rectangular | 120 cm x 80 cm x 90 cm | 85 | ~734 L |
| Round leaf bin | Cylinder | Diameter 60 cm, Height 85 cm | 100 | ~240 L |
| Tapered planter bin | Frustum | Top 70 cm, Bottom 50 cm, Height 90 cm | 75 | ~204 L |
| Corner storage bin | Triangular prism | Base 60 cm, Height 40 cm, Length 120 cm | 90 | ~130 L |
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.