Free Pool Volume Calculator for Rectangular, Round, and Oval Pools, Gallons, Liters, and Fill Time
Use this browser-side calculator to turn measurements and product assumptions into a practical first-pass estimate. Review the formula, replace defaults with real project data, and verify requirements before purchasing or building.
Use the calculator
How to use this calculator
1. Measure consistently
Use the units shown beside each field and recheck the dimensions that drive the calculation.
2. Replace defaults
Use actual package coverage, spacing, waste, price, product dimensions, or project ratios whenever they are known.
3. Verify before ordering
Compare the result with drawings, manufacturer data, supplier units, site conditions, and applicable requirements.
12 useful features
Three pool shapes
Built into this calculator for a clearer planning workflow.
Length / diameter
Built into this calculator for a clearer planning workflow.
Width
Built into this calculator for a clearer planning workflow.
Shallow depth
Built into this calculator for a clearer planning workflow.
Deep depth
Built into this calculator for a clearer planning workflow.
Average depth
Built into this calculator for a clearer planning workflow.
Surface area
Built into this calculator for a clearer planning workflow.
Cubic-foot volume
Built into this calculator for a clearer planning workflow.
US gallons
Built into this calculator for a clearer planning workflow.
Liters
Built into this calculator for a clearer planning workflow.
Cubic meters
Built into this calculator for a clearer planning workflow.
Optional fill-time estimate
Built into this calculator for a clearer planning workflow.
Formula and reference table
| Concept | Formula / meaning | Planning note |
|---|---|---|
| Average depth | (shallow + deep) ÷ 2 | Simple sloped-bottom approximation |
| Rectangle area | length × width | Surface plan area |
| Oval area | π ÷ 4 × length × width | Ellipse approximation |
| Gallons | cubic feet × 7.48052 | US gallons |
Pre-order checklist
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Quick knowledge check
What is the safest way to use a construction calculator?
Microlearning guide
Geometry is one layer
A correct area, volume, spacing, or slope formula does not replace structural, product, installation, or code requirements.
Whole units matter
Sheets, bags, boards, rolls, bundles, and stock pieces are purchased as discrete units, so planning often requires rounding upward.
Assumptions drive results
Waste, spacing, product coverage, price, pitch, dimensions, or layout choices can change an estimate more than extra decimal places.
Examples and practical uses
Early planning
Compare quantity or cost scenarios before requesting material quotes.
Purchase cross-check
Compare the result with package coverage, stock lengths, supplier recommendations, and project drawings.
Formula review
Use the reference table to independently reproduce the main arithmetic.
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Frequently asked questions
How is average depth calculated?
The calculator uses the arithmetic mean of shallow and deep depths, which is a practical approximation for a steadily sloped bottom.
Can it calculate round pools?
Yes. Choose Round and enter the diameter in the length field.
Does it handle irregular pool shapes?
Not directly. Divide an irregular pool into simpler sections and combine their estimated volumes.
Why might actual pool volume differ?
Steps, benches, curved walls, freeboard, slopes, and the actual operating water level can change volume.
Is fill time exact?
No. It divides estimated gallons by the entered flow rate. Real flow can vary with pressure, hose size, restrictions, and supply conditions.