Expert Verified Updated: March 2026

Kidney-Shaped Pool Volume Calculator

Accurately calculate the exact gallon capacity of a kidney-shaped pool using measurements of the wide end, narrow end, and length.

Quick Conclusion
To find the volume of a kidney-shaped pool, measure the widest part (A), the narrowest part (B), and the total length (L). The formula is: (A + B) * L * 0.45 * Average Depth * 7.5 = Gallons.

Technical Comparison

ShapeMultiplier ConstantMeasurement Needs
Rectangle1.0Length & Width
Oval0.785Length & Width
Kidney0.45Length, Width A, Width B
Round0.785Diameter × 2
Kidney-shaped pools are notoriously difficult to dose properly because owners often guess the volume or treat them like ovals, leading to severe under-dosing or over-dosing of harsh chemicals.

Actionable Steps

1. Measure the absolute longest part of the pool (Length). 2. Measure the widest part of the wide lobe (A). 3. Measure the widest part of the narrow lobe (B). 4. Use the calculator to determine exact gallons.

Pro-Tip

If your kidney pool has an extreme curve or 'bite' taken out of the middle, subtract about 5% from the final gallon calculation to prevent over-dosing chlorine.

Frequently Asked Questions

Why use 0.45 in the formula?

The 0.45 multiplier is a standardized geometric constant used specifically to estimate the surface area of irregular, kidney-like shapes.

How do I find average depth?

Add the depth of the deep end to the depth of the shallow end, and divide that number by 2.

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