# Round Pool Volume Calculator

URL: https://speedycalculator.com/calculators/construction/round-pool-volume/
Last updated: 2026-10-25

> The round pool volume calculator finds how many gallons or litres an above-ground or round pool holds from its diameter and water depth, the weight of the water, the surface area and the time to fill.

## Inputs

- Diameter (ft, m, in, yd, cm)
- Water depth (in, cm, mm, ft, m)
- Fill flow rate (gpm, L/min, gph, m³/h, ft³/s, L/s)

## Results

- Pool volume
- Surface area
- Weight of water
- Time to fill

## Formula

```
Volume = π × (D ÷ 2)² × water depth
Gallons ≈ D² × depth × 5.9 (feet)
```

## Explanation

Above-ground pools are sized by diameter and wall height (for example 24 ft × 52 in), but they are normally filled to about 6 in below the top of the wall. Use the water depth, not the wall height, to dose chemicals correctly.

### How to use the Round Pool Volume Calculator

- **Diameter**
- **Water depth**
- **Fill flow rate**
- Every result field is editable: type into **Pool volume** and **Water depth** plus every other field update to match.

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter the diameter, the water depth and your fill flow rate.

### Common above-ground pools (48 in water depth)

DiameterUS gallonsLitres12 ft3,38412,81015 ft5,28820,01618 ft7,61428,82321 ft10,36439,23124 ft13,53651,24127 ft17,13264,85230 ft21,15180,06433 ft25,59296,877

### Tips for an accurate estimate

- Measure inside dimensions of tanks and pools – wall thickness can change the volume noticeably.
- Use the average depth for pools with a sloping floor.
- Remember the weight: water weighs about 8.34 lb per US gallon (1 kg per litre), so large volumes need solid support.
- Check whether a figure is in US gallons, imperial gallons or litres before ordering chemicals or equipment.

### Common mistakes to avoid

- Using wall height instead of water depth for above-ground pools.
- Assuming a horizontal tank's volume is proportional to the liquid level – it is not.
- Mixing up flow units such as GPM, GPH and litres per minute.

### Inputs explained

FieldWhat to enterDiameterUnits: ft, m, in, yd, cmWater depthUnits: in, cm, mm, ft, mFill flow rateUnits: gpm, L/min, gph, m³/h, ft³/s, L/s

### What each result means

- **Pool volume** = pi×([Diameter]÷2)^2×[Water depth]
- **Surface area** = pi×([Diameter]÷2)^2
- **Weight of water** = [Pool volume]×1000
- **Time to fill** = [Pool volume]÷[Fill flow rate]

## Worked example

Inputs — Diameter: 24 ft; Water depth: 48 in; Fill flow rate: 10 gpm.

Results — **Pool volume = 13,536 US gal**; Surface area = 452.4 ft²; Weight of water = 56.5 US ton; Time to fill = 22.6 h.

## FAQ

**How many gallons is a 24 ft round pool?**
About 13,500 gallons at 48 in of water (52 in wall).

**How many gallons in a 15 ft round pool 4 ft deep?**
About 5,300 gallons.

**Is the water depth the same as the wall height?**
No – fill to about the middle of the skimmer, usually 6 in below the wall top.

**What formula does the Round Pool Volume Calculator use?**
Volume = π × (D ÷ 2)² × water depth.