Calculation Results
Results include all baskets, soil adjustments, bag estimates, mix quantities, and costs.
Basket Breakdown
| Basket | Shape | Quantity | Gross volume | Net soil each | Adjusted total |
|---|
Soil Mix Quantities
| Component | Percentage | Required amount |
|---|
Calculation Steps
Formula Used
Cylindrical basket: V = πr²h. Diameter equals twice the radius. The formula uses internal dimensions after liner and rim adjustments.
Tapered basket: V = πh(R² + Rr + r²) ÷ 3. This is the frustum formula. The calculator interpolates the diameter when rim space reduces fill height.
Bowl basket: V = 2πr²h ÷ 3. This treats the bowl as a half ellipsoid. It provides a practical soil estimate for curved hanging baskets.
Rectangular planter: V = length × width × height. The calculator subtracts liner thickness from internal dimensions. It then applies the selected fill percentage.
How to Use
- Select each basket shape and measurement unit.
- Enter dimensions, quantity, liner, rim, drainage, and displacement values.
- Add more baskets when comparing several sizes or shapes.
- Set soil mix percentages so the total equals 100%.
- Choose a bag size, cost method, and primary result unit.
- Select Calculate Soil to view totals, bags, leftovers, and cost.
Example Soil Requirements
| Basket | Approximate dimensions | Estimated soil before allowances |
|---|---|---|
| Small round basket | 25 cm diameter × 15 cm depth | About 7.4 litres |
| Medium round basket | 35 cm diameter × 18 cm depth | About 17.3 litres |
| Large tapered basket | 45 cm top, 25 cm bottom, 22 cm depth | About 22.5 litres |
| Rectangular planter | 60 cm × 20 cm × 18 cm | About 21.6 litres |
Saved Calculation History
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Frequently Asked Questions
How much extra soil should I buy?
A combined allowance of 10% to 15% usually covers settling and small spills. Larger coir mixes may settle more. The calculator lets you set both percentages.
Should drainage material count as soil?
No. Drainage material occupies basket volume. This calculator subtracts its estimated volume before reporting soil requirements.
How does liner thickness affect the result?
A thick liner reduces internal basket dimensions. The calculator subtracts liner thickness from each applicable side before calculating usable volume.
What does plant displacement mean?
Roots and nursery root balls already occupy basket space. Enter their estimated percentage to avoid buying unnecessary soil.
Can I calculate several basket sizes together?
Yes. Add another basket and choose its shape, dimensions, and quantity. The final result combines every basket.
Why are bag quantities rounded upward?
Retail bags are normally sold as whole units. The exact requirement is shown, while the purchase quantity rounds upward.
Can I use a custom soil bag size?
Yes. Choose Custom bag size, then enter litres, cubic feet, or gallons. The calculator converts it automatically.
What happens when mix percentages do not equal 100%?
The calculator displays a validation warning. You can correct the values or use the normalise button.
Is the bowl calculation exact?
It is an estimate based on a half-ellipsoid shape. Irregular woven baskets may require a practical test fill.
Can results be exported?
Yes. Copy the summary, download CSV, create a PDF, or print the result section directly.
Does the calculator save personal data?
No personal data is requested. Calculation history stays in your browser until you clear it.