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Pool Volume Calculator

A rectangle is length times width times a single depth. A circle is π r² times that depth. Output is cubic meters, liters, and US gallons. Freeform hoppers and spa benches are omitted. Estimate only, not a fill ticket.

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How to estimate pool volume

  1. Pick rectangle or circle, then feet or meters for every size on the form.
  2. For a rectangle enter length, width, and a single depth. For a circle enter radius and depth.
  3. Read cubic meters, liters, and US gallons. Liters are m³ × 1000. US gallons divide m³ by 0.003785411784.
  4. A hopper, beach entry, or spa bench needs extra geometry you add yourself. Not a fill ticket.

Constant-depth pool volume

Rectangle or circle, one depth

RectangleL × W × D after converting to meters
Circleπ r² D after converting to meters
Litersm³ × 1000
US gallonsm³ / 0.003785411784
Default rectangle20 ft by 10 ft by 5 ft
AdviceEstimate only. Not a fill ticket or a tank stamp.

What this pool volume includes

The water is a prism or a cylinder of one depth. A typical backyard pool slopes from shallow to deep. Using the deep-end depth overstates gallons. Using the shallow-end depth understates them. A manufacturer tank with a stamped capacity is the tank volume page, which models vertical, horizontal, and box tanks, not a swimming pool freeform.

How gallons are computed

Feet convert with 0.3048 m. A rectangle volume in m³ is length × width × depth in meters. A circle is π r² times depth. Liters multiply m³ by 1000. US gallons divide m³ by 0.003785411784. Depth is one number, not a two-slope average unless you type that average yourself.

Hoppers, spas, and fill tickets

A fill ticket from a water hauler uses a meter, not this prism. Chemical dosing uses gallons as a starting guess. Freeform kidney shapes, tanning ledges, and attached spas are extra volumes. Not structural design of a shell.

Use cases

A rectangular 20 by 10 by 5 ft sketch, or a round stock-tank pool. Not a permit and not a plaster takeoff.

Limits

One depth. Rectangle or circle only. Estimate only, not a fill ticket. CZNull does not receive the sizes.

Pool volume questions

Does a rectangle use one depth?
Yes. Type an average depth if the floor slopes.
Is this a fill ticket?
No. It is an estimate. A hauler meters the water.
How do I model a circle?
Pick circle and enter radius and depth. Length and width hide.
Where is a closed tank instead of a pool?
Use the tank volume calculator for vertical, horizontal, or box tanks.
Which gallon is this?
US gallons, from cubic meters divided by 0.003785411784.
Is this structural design?
No. It is a volume estimate, not code approval.