# Pool Volume Calculator: Gallons, Surface Area & Robot Size | Robot Pool Cleaner Guide

> Free pool volume calculator for rectangular, round, oval and kidney pools: gallons, floor and wall area, pump turnover rate and the robotic pool cleaner size your pool needs.

- Source: https://robotpoolcleanerguide.com/tools/pool-volume-calculator/
- Markdown version: https://robotpoolcleanerguide.com/tools/pool-volume-calculator.md

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- Pool volume calculator

# How many gallons is your pool?
Volume drives chemical dosing and pump sizing; surface area is what decides which pool robot fits. Pick your shape, enter the dimensions and get both.

Pool shapeRectangleRoundOvalKidney / freeform
Length (ft)
Width (ft)
Narrow-end width (ft)
Diameter (ft)

Shallow depth (ft)
Deep depth (ft)

Above-ground pool? Enter the same number for shallow and deep (the wall height minus a few inches for the water line).

## The formulas

- **Rectangle:** length × width × average depth × 7.48
- **Round:** π × (diameter ÷ 2)² × average depth × 7.48
- **Oval:** length × width × 0.785 × average depth × 7.48
- **Kidney:** (width A + width B) × length × 0.45 × average depth × 7.5
Average depth is (shallow + deep) ÷ 2 for a steadily sloped floor; hopper-bottom or deep-end pools run a little off, so treat the answer as ±5–10%. There are 7.48 US gallons in a cubic foot.

## Why surface area matters for robots
A robot doesn't care how many gallons you have. It cares about the floor it has to cover, thewalls it has to climb and whether it needs to scrub the waterline. A shallow 16×32 ft pool and a deep 16×32 ft pool have the same floor but very different wall area, so size up for deep pools and heavy debris. Take your floor area to the [robot matcher](https://robotpoolcleanerguide.com/tools/robot-matcher/), or read[how robot coverage ratings work](https://robotpoolcleanerguide.com/posts/robotic-pool-cleaner-coverage-ratings-explained/).

## FAQ

### How do I calculate pool volume in gallons?
For a rectangular pool: length × width × average depth × 7.48. Average depth is (shallow depth + deep depth) ÷ 2 for a sloped floor. Round pools use π × radius² × depth × 7.48; ovals use length × width × 0.785 × depth × 7.48; kidney pools use (A + B) × length × 0.45 × depth × 7.5.

### How big a robot do I need for my pool volume?
Robots clean surfaces, not volume, so floor area matters more than gallons. Pick a cordless robot rated for roughly 1.5× your floor area, or a corded robot rated for a pool longer than yours. The robot matcher does this for you.