- Rectangular volume: V = L × W × H
- Cylindrical volume: V = π × (D/2)² × H
- Headspace: Veffective = V × (1 − headspace%)
- Mass estimate: m(g) = density(g/mL) × Veffective(mL)
- Select the container shape that matches your bin.
- Enter internal dimensions and choose centimeters or inches.
- Set headspace to avoid overfilling and moisture issues.
- Select a material preset or adjust the density value.
- Press Calculate to see volume, mass, and usage estimates.
| Container | Dimensions | Headspace | Density | Effective Volume | Estimated Mass |
|---|---|---|---|---|---|
| Small kitchen caddy | 20×15×18 cm | 10% | 0.45 g/mL | 4.86 L | 2.19 kg |
| Medium airtight bin | 30×20×25 cm | 12% | 0.45 g/mL | 13.20 L | 5.94 kg |
| Round bucket | Ø 25 cm × 30 cm | 15% | 0.45 g/mL | 12.52 L | 5.63 kg |
Match container volume to weekly collection
This calculator converts your bin’s internal dimensions into effective liters after subtracting headspace. Use it to align capacity with how often you collect grounds from cafés or your kitchen. For example, a 10–15% headspace keeps scoops and labels clear, while still preserving most of the usable volume.
Use realistic bulk density for better mass estimates
Volume alone is not enough when you plan lifting, shelving, or transport. Bulk density converts milliliters to grams. Dry grounds often settle near 0.45 g/mL, while whole beans can be lighter around 0.36 g/mL. Blends with compost additives may pack higher. Adjust the density field if your material is wetter or more compact.
Headspace improves handling and reduces spill risk
Bins filled to the brim are harder to stir, scoop, and close without mess. By reserving headspace, the calculator estimates a practical “working capacity,” not just theoretical volume. This matters when you add carbon materials, mix with browns, or portion grounds into smaller bags for indoor plants and seed-starting.
Moisture control changes storage outcomes
Dry material stores longer and stays free-flowing. If you store damp grounds, mass increases and mold risk rises, especially in sealed containers. The mass estimate helps you gauge weight on shelves, but good practice is to dry grounds first, then store in breathable or loosely vented bins if humidity is high.
Plan rotation and usage with a daily rate
If you enter a daily use rate, the calculator estimates how many days and weeks your stored mass will last. This supports rotation: label batches, use older grounds first, and avoid long holds that attract pests. A consistent rate also helps you decide whether one large bin or multiple smaller bins fit your workflow. To compare bins, run multiple scenarios and note kilograms. A 15 L bin of dry grounds can approach 6–7 kg, which affects handles and shelves. Smaller bins simplify rotation and drying, while larger bins reduce transfers. Choose what suits your space best.
1) Should I measure the inside or outside of the container?
Always measure internal dimensions. Wall thickness, rounded corners, and lid shapes reduce usable space, so inside measurements produce a more accurate effective volume and mass estimate.
2) What headspace percentage is best?
For most bins, 10–15% works well. Choose higher headspace if you scoop frequently, store in humid areas, or need room for desiccants, labels, or mixing before use.
3) Why does density affect the result so much?
Density converts volume into weight. Fluffier material stores less mass per liter, while compact or damp material stores more. Using the closest density gives better lifting, shelving, and usage planning.
4) Can I use this for wet grounds?
Yes, but increase the density to reflect moisture and compaction. Also reduce storage time and improve airflow to limit mold. Drying before storage is usually safer and easier.
5) How do I estimate my daily use rate?
Track one week: weigh what you apply to compost or soil amendments, then divide by seven. Enter that daily average to see estimated days and weeks of coverage.
6) Why are there cups and quarts in the results?
Many household scoops and containers are labeled in cups or quarts. Providing these units helps you portion grounds consistently, especially when following compost recipes or indoor potting mixes.