When to use this calculator
Estimate soil fill volume for a tapered round plant pot. A circular conical-frustum approximation using dimensions at the filled soil level.
Explore the plant spacing, soil & seed calculators for other questions in this topic. For a related calculation, use the Triangular Plant Spacing Calculator: Estimate plant density in a staggered equilateral-triangle arrangement.
PUTTING IT INTO PRACTICE
Tapered Planter Soil: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Internal top diameter (cm) | 40 |
| Internal bottom diameter (cm) | 20 |
| Filled height (cm) | 30 |
| Result | 21.991149 L |
- Check the input labels and enter the example values above.
- Apply the relationship: Frustum litres = πh(D²+Dd+d²)/(12×1000).
- The result is 21.991149 L, rounded for display.
How to interpret your result
A circular conical-frustum approximation using dimensions at the filled soil level.
Usable area and boundaries affect actual plant count. Product-specific seed rates and germination assumptions are entered rather than recommended. Volume-based soil estimates can change with settling, moisture and compaction.
Frequently asked questions
Does a plant-count estimate choose suitable crop spacing?
No. You choose spacing appropriate to the crop and growing conditions. The calculator translates that spacing into a geometric count.
When is the tapered planter soil calculator useful?
Estimate soil fill volume for a tapered round plant pot. A circular conical-frustum approximation using dimensions at the filled soil level.
How do I use the tapered planter soil calculator?
Enter internal top diameter (cm), internal bottom diameter (cm), filled height (cm). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Frustum litres = πh(D²+Dd+d²)/(12×1000).
What should I check before using the result?
A circular conical-frustum approximation using dimensions at the filled soil level.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
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