Rectangular pool
Area = length × width
The entered dimensions describe the water surface, not the outside of the pool structure.
How it works
How to calculate pool volume.
The calculator finds the water-surface area, applies the average depth, and converts one canonical cubic-meter result into your preferred units.
Round pool
Area = π × (diameter ÷ 2)²
The round mode uses the circle formula directly.
Oval pool
Area = π × (length ÷ 2) × (width ÷ 2)
Oval is modeled as a true ellipse using the major and minor axes.
Water volume
Volume = surface area × average depth
For shallow and deep ends, average depth is their arithmetic mean.
Measure with care
Why pool-volume estimates can differ.
Find the average depth
A flat-bottom depth can be used directly. For an approximately uniform slope, add the shallow and deep depths and divide by two.
US gallons and cubic feet
Measivo converts the calculated physical volume with exact unit definitions. It does not use a rounded gallons-per-cubic-foot shortcut.
Irregular and hopper bottoms
Steps, benches, integrated spas, hopper bottoms, and complex floor profiles can make the real capacity differ from a simple geometric estimate.
Chemical and equipment use
For chemical dosing or equipment settings, use the most accurate pool volume available and follow the product or equipment manufacturer’s instructions.
What the estimate assumes
A geometric estimate with visible limits
- Dimensions describe the water surface: a rectangle, a circle, or an ellipse.
- One depth is treated as the known average water depth.
- Shallow and deep ends are averaged and assume the floor changes approximately uniformly between them.
- Steps, benches, integrated spas, hopper bottoms, and freeform outlines are not modeled.
- The result estimates water volume only; it does not calculate chemicals, water weight, fill time, cost, flow, pump, or heater sizing.
Exact conversions, practical measurements
The formula stays in canonical cubic meters, then uses the shared unit converter for US liquid gallons, cubic feet, liters, and cubic meters.
For treatment or equipment decisions, verify the best available pool capacity and follow the applicable manufacturer instructions.
Reference sources
Pool volume questions
Frequently asked questions
How many gallons are in my pool?
Choose the pool shape, measure the water surface, and enter an average depth or shallow and deep depths. The calculator multiplies surface area by average depth and converts the result to US gallons.
How do I calculate average pool depth?
For a floor that slopes approximately uniformly, add shallow depth and deep depth and divide by two. Complex floor profiles need more detailed measurements.
How many gallons are in a cubic foot?
One cubic foot equals exactly 1,728 cubic inches, and one US liquid gallon equals exactly 231 cubic inches, so the conversion is 1,728 ÷ 231 US gallons per cubic foot.
How do I calculate a round pool?
Use π times the square of half the diameter for the surface area, then multiply by average depth.
How do I calculate an oval pool?
Treat the oval as an ellipse: multiply π by half the length, half the width, and the average depth.
Is shallow depth plus deep depth divided by two always accurate?
No. It is appropriate for an approximately uniform slope, but hopper bottoms, benches, steps, and other complex floor profiles can change the real volume.
Why is my pool manufacturer’s listed capacity different?
Manufacturer capacity may reflect the actual shell, fill line, steps, benches, or a more detailed floor profile than this geometric model.
Can I use this volume for pool chemicals?
This page provides a geometric volume estimate, not chemical dosing. Use the most accurate pool volume available and follow the chemical product manufacturer’s instructions.
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