Swimming Pool Volume CalculatorFree online other calculator — instant results, no sign-up
Estimate rectangular pool capacity using average water depth.
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About the Swimming Pool Volume Calculator
The Swimming Pool Volume Calculator estimates the water capacity of a rectangular pool from its length, width, and average water depth in metres. It converts the calculated volume into litres to help you plan filling and understand how much water the pool holds. With the default dimensions of 8 m by 4 m and an average depth of 1.5 m, the estimated capacity is 48,000 L.
- Length (m)
- The internal length of the water-filled pool in metres, with a default of 8 m.
- Width (m)
- The internal width of the water-filled pool in metres, with a default of 4 m.
- Average depth (m)
- The average vertical distance from the water surface to the pool floor in metres, with a default of 1.5 m.
Formula and method
V = L × W × d_avg × 1,000 = 8 × 4 × 1.5 × 1,000 = 48,000 L
- VEstimated pool water volume in litres.
- LInternal pool length in metres; in the result unit, L instead denotes litres.
- WInternal pool width in metres.
- d_avgAverage water depth across the pool's footprint in metres.
- 1,000Conversion factor from cubic metres to litres: 1 m³ equals 1,000 L.
Multiply the internal length by the internal width to obtain the rectangular footprint area. Multiply that area by the average water depth to estimate volume in cubic metres, then multiply by 1,000 to convert to litres. For the default inputs, 8 × 4 = 32 m², 32 × 1.5 = 48 m³, and 48 × 1,000 = 48,000 L.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- Length8 m
- Width4 m
- Average depth1.5 m
Results
- Result48,000 L
How to use the Swimming Pool Volume Calculator
- 1Measure the pool's internal length and width in metres, excluding walls, coping, and the surrounding deck.
- 2Determine the average water depth at the intended fill level, rather than measuring to the top of the pool wall.
- 3Enter the length and width; the default values are 8 m and 4 m.
- 4Enter the average depth; the default value is 1.5 m.
- 5Read the estimated capacity in litres; the default inputs produce 48,000 L.
Reading your result
The Result row shows the estimated total water volume in litres at the depth you entered. A result of 48,000 L means the rectangular water-filled space holds approximately 48,000 litres, equivalent to 48 cubic metres. It is not the additional water needed to top up a pool that already contains water.
Limitations
The calculation assumes a rectangular footprint with vertical sides and an average depth representative of the full footprint. Rounded corners, tapered walls, steps, benches, and other features that displace water can make the estimate too high. Irregular floors require an area-weighted average depth; simply averaging the shallowest and deepest measurements is not always valid. Results depend on measurement accuracy and the chosen water level, and this tool does not calculate chemical doses or filling time.
Common questions
How do I find average depth for a pool with a sloping floor?+
For a rectangular pool with a floor that slopes uniformly from one end to the other, average depth is (shallow-end water depth + deep-end water depth) ÷ 2. If the pool has flat sections, a diving well, or uneven slopes, divide it into sections and weight each section's average depth by its footprint area.
Should I measure depth to the pool rim or to the water surface?+
Measure from the floor to the actual or intended water surface. Measuring to the rim overestimates capacity when the normal water level is below it.
Can I use this calculator for a round or kidney-shaped pool?+
Not directly: multiplying overall length by overall width assumes a rectangle and generally overestimates those shapes. Use a shape-specific volume calculation or divide the pool into measurable sections and add their volumes.
Does the 48,000 L default result account for pool steps or benches?+
No. It represents an unobstructed rectangular volume of 8 m × 4 m × 1.5 m. Submerged steps and benches displace water, so their submerged volume must be subtracted unless already accounted for in the average depth.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
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Results are estimates for informational purposes and are not financial, medical or legal advice.