Pool Volume, Fill Time and Water Cost Calculator
Estimate pool gallons, liters, fill time, and editable water cost for rectangular, circular, and oval pools.
How to use the pool volume calculator
- Measure the actual project. Break irregular work into separate sections and record finished dimensions consistently.
- Enter the core measurements. The quick view focuses on project geometry; add or subtract sections where the calculator supports multiple areas.
- Review purchasing assumptions. Open Advanced inputs to replace example prices, waste, coverage, density, pack size, minimum order, or delivery assumptions with current project information.
- Calculate and verify. Review the formula, limitations, whole-unit rounding, product instructions, and supplier requirements before purchasing.
Key inputs covered: Pool shape, Pool length, Pool width, Pool diameter, Depth method, Shallow depth, Deep depth, Constant / average depth, Measured fill rate, Water and sewer example price.
Result coverage: The pool volume calculator reports 5 separate quantities so the primary estimate and its supporting purchase or planning values can be checked together.
How the estimate works
Plan area × average depth produces cubic feet; 7.48052 converts cubic feet to U.S. gallons, then measured hose flow and utility price produce time and cost.
A 30 × 15 ft rectangle averaging 5.5 ft contains about 18,515 gallons.
Assumptions, rounding, and limitations
Dimensions are treated as finished measurements. Only deductions and allowances entered above are included. Decimal measurements display to two places; purchase quantities round up when a whole container or piece is required.
- Oval mode assumes an ellipse and sloped depth assumes the two end depths average across the pool.
- Actual shells, steps, benches, coves, displacement, waterline, and measured fill meter can change volume.
- This calculator provides no chemical dosing, circulation, structural, barrier, or code advice.
Sources and review
These references support unit conversions and selected planning assumptions. Product instructions and local requirements control the actual project.
- NIST Handbook 44 — current unit-conversion tables
- Pentair 2025–2026 engineering data — pool-volume formulas
Last reviewed: 2026-10-09
Editorial process
BuildPlanCalc publishes the formula, editable assumptions, limitations, and supporting references so the estimate can be checked rather than treated as a black box. See the calculation and review methodology, or report a correction.
Frequently asked questions
Are the results exact?
No. Results are planning estimates based on the dimensions and assumptions entered. Confirm product coverage, site conditions, and ordering rules with the supplier.