A 24-Foot Round Pool Holds Approximately 13,500 Gallons

A standard 24-foot round pool with an average depth of 4 feet holds about 13,500 gallons of water. This estimate assumes a uniform depth; deeper pools (e.g., 5-6 ft) may reach 16,000+ gallons. Always measure actual depth for precision, as shape and slope affect total volume.

How to Calculate Pool Gallons Accurately

Use this formula for round pools:

Volume (gallons) = π × radius² × average depth × 7.48
  • Radius: Half the diameter (24 ft ÷ 2 = 12 ft).
  • Average depth: (Shallow end + deep end) ÷ 2. Example: (3 ft + 5 ft) ÷ 2 = 4 ft.
  • 7.48: Converts cubic feet to gallons.

Gallon Estimates by Depth (24-Ft Round Pool)

Average Depth (ft) Estimated Gallons Use Case
3.5 ft 11,800 Shallow play pools
4 ft 13,500 Standard family pools
5 ft 16,900 Diving or deep-end pools

Factors Affecting Pool Volume

  • Shape irregularities: Oval or freeform pools require different formulas.
  • Sloped bottoms: Gradual slopes increase volume vs. flat-bottom pools.
  • Liner thickness: Subtract ~1-3% for vinyl liner pools.
  • Water displacement: Account for swimmers, toys, or steps (add ~10% for safety).

Quick Reference for Common Pool Sizes

  1. 18-ft round (4 ft deep): ~7,600 gallons
  2. 21-ft round (4.5 ft deep): ~10,400 gallons
  3. 27-ft round (5 ft deep): ~19,000 gallons

When to Measure Precisely

  • Adding chemicals (dosage depends on exact gallons).
  • Installing a heater or pump (sizing requires accurate volume).
  • Filling/draining (water cost estimates).

Pro tip: Use a water meter to track fill-up gallons for absolute accuracy.