Round Pool Gallons Calculator

Advanced calculator for round pools with precise volume results and options. Choose units, input diameter, shallow and deep depths for accuracy and reliability. Includes fill percentage, liters conversion, and estimated fill time for practical planning. Export results as CSV and PDF with ease anytime.

Input

White theme
All inputs use this unit.
ft
ft
ft
ft
ft
Reduces average depth by this amount.
For estimated fill time (optional).

Results

All values dynamically update after calculation.
—
Water Volume (gallons)
—
Water Volume (liters)
—
Estimated Fill Time
Timestamp Units Diameter Avg Depth Fill % Volume ft³ Gallons Liters m³ Surface Area ft² Circumference Flow Rate Fill Time
No calculations yet.

Quick Facts

  • Formula: V = π × r² × h (cylindrical volume).
  • US gallons per ft³: 7.48052.
  • Liters per gallon: 3.78541.
  • Average depth with slope: (shallow + deep) / 2.

Example Data

Example Units Diameter Depth / Shallow Deep Offset Fill % Approx Gallons
Backyard Round 24×4ft244—0.29512,700
Garden Splash 12×3.5ft123.5—0.01002,650
Family Round 18, 3–5 slopeft18350.3906,700
Approximate gallons shown for illustration; use the calculator for exact values.

Typical Round Pool Sizes — Gallons at Common Depths

Diameter (ft) Gallons @ 3 ft Gallons @ 4 ft Gallons @ 5 ft
Auto-filled on load.
Assumes cylindrical walls, 100% fill, no offset.

Gallons to Liters — Quick Conversion

Gallons Liters
Auto-filled on load.
Rounded to whole liters for quick reference.

Formulas Used

A round above‑ground or in‑ground pool is approximated as a right circular cylinder. The water volume in cubic feet is Vft³ = π × (Dft/2)² × Hft, where D is the water diameter and H is the average water depth.

  • Average depth (sloped floor): H = (Hshallow + Hdeep) / 2
  • Offset below rim reduces H by the entered amount.
  • Gallons: G = Vft³ × 7.48052
  • Liters: L = G × 3.78541
  • Cubic meters: m³ = L / 1000
  • Surface area: A = π × (Dft/2)²
  • Circumference: C = π × D (reported in chosen units)
  • Fill percentage scales all volumes by Fill% / 100.

How to Use This Calculator

  1. Select your preferred measurement unit.
  2. Enter pool diameter measured at the waterline.
  3. Choose depth mode: uniform or averaged shallow/deep.
  4. Optionally enter an offset if water sits below the rim.
  5. Adjust the fill percentage slider if not filling to 100%.
  6. Optionally provide a flow rate to estimate fill time.
  7. Click Calculate to populate results and KPIs.
  8. Use Download CSV or Download PDF to export.

FAQs

Most round pools are close to cylindrical. Minor wall taper or floor curvature introduces small errors, typically within a few percent for sizing chemicals and pumps.

Measure the waterline diameter, not coping-to-coping, to reflect the actual contained water. If walls bow, take several readings and average.

Enter shallow and deep depths; the tool averages them. You can also deduct a waterline offset if the pool isn’t filled to the rim.

Yes. Choose feet/inches, inches only, centimeters, or meters. The calculator converts internally and returns gallons, liters, and cubic meters.

Provide a flow rate in gpm or lpm. The tool divides adjusted gallons by gpm to estimate time, then formats into hours and minutes.
© CodingAce • Round Pool Gallons Calculator

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.