Accurate Pool Volume Calculator: Customize Sections, Features & Adjustments

Measure length, width and depth, key them into the calculator, then hit “Calculate.” The app multiplies cubic feet by 7.48052 to return gallons—so a 1,500 ft³ pool holds 11,221 gal (USGS, 2020). Subtract stairs or benches for precision. That figure lets you dose chemicals, size heaters and predict water costs.

Pool Volume Calculator

Pool Section

Pool Feature (Optional)

Enter estimated volume to subtract for curved walls or other irregularities.

How to use the tool

Step-by-step

  • Enter section data. For each panel choose Flat or Sloped, then add dimensions.
    Example A: Flat—Length = 25 ft, Width = 15 ft, Depth = 4 ft.
    Example B: Sloped—Length = 30 ft, Width = 15 ft, Start Depth = 3 ft, End Depth = 8 ft.
  • Add features to subtract water. Type a name (e.g., “Bench”), then its Length = 6 ft, Width = 2 ft, Avg Depth = 1 ft.
  • Adjustment for irregularities (gal). Optional: type 250 or 300 if you have curved walls.
  • Click “Calculate Pool Volume.” Totals appear in cubic feet and gallons; the tool auto-subtracts features and irregularities.

Formulas used

  • Flat section
    $$V_{flat}=L\,W\,D$$
  • Sloped section
    $$D_{avg}= rac{D_{start}+D_{end}}{2}$$ $$V_{sloped}=L\,W\,D_{avg}$$
  • Total pool
    $$V_{pool}=ΣV_{sections}-ΣV_{features}$$
  • Gallons conversion
    $$V_{gal}=V_{ft^{3}}\times7.48052$$

Example calculations

  • Example A (rectangular): $$25\times15\times4=1500\,ft^{3}$$
    Gallons = 1500 × 7.48052 = 11,221 gal.
  • Example B (sloped): Average depth = (3+8)/2 = 5.5 ft.
    Volume = 30 × 15 × 5.5 = 2475 ft³.
    Gallons = 2475 × 7.48052 = 18,509 gal.

Quick-Facts

  • 1 ft³ = 7.48052 US gal (USGS Water Science School, 2020).
  • Residential pools should turn over every 8 h (ANSI/APSP-11, 2022).
  • Heating 1 gal 1 °F needs 8.34 BTU (Energy.gov, 2021).
  • Free-chlorine target is 1–3 ppm for safety (CDC Model Aquatic Health Code, 2022).
  • NSF/ANSI 50 certifies pool filters for flow and hygiene (NSF International, 2023).

FAQ

What measurements do you need?

You need each section’s length, width, and depth; also the start and end depths for slopes (ANSI/APSP-4, 2021).

How do you handle a sloped floor?

The tool averages the shallow and deep depths, then multiplies by length and width for volume.

Why subtract feature volumes?

Stairs, benches, or ledges displace water; subtracting prevents chemical overdosing (CDC, 2022).

Is the 7.48052 conversion factor exact?

Yes, one cubic foot equals 7.48052 US gallons at 39.2 °F (USGS, 2020).

How does volume affect chlorine dosing?

One ppm requires 0.00013 oz chlorine per gallon; exact volume avoids under- or over-chlorination (CDC, 2022).

How can I size a heater from volume?

Multiply gallons by 8.34 BTU for each °F rise, then divide by desired heat-up hours (Energy.gov, 2021).

Can the calculator handle free-form pools?

You break irregular shapes into simple sections and enter each; use the adjustment field for curves.

How often should I recalculate volume?

Re-measure after renovations, liner changes, or feature additions to keep chemical and energy estimates current.

Is this tool helpful?

Thanks for your feedback!

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