Pool Water Volume Calculator

Calculate your pool's water volume in gallons and liters for proper chemical treatment and filling

Pool Dimensions
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ft
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Average depth = (shallow end depth + deep end depth) ÷ 2
Total Water Volume -
Surface Area -
Perimeter -
Chemical Estimate -
Chemical Treatment Guide
Chlorine (3ppm) -
Shock Treatment -
pH Adjuster -
Algaecide -
Frequently Asked Questions
How do I calculate my pool's water volume?

Pool water volume depends on the shape and dimensions of your pool. Use our calculator above by selecting your pool shape and entering the measurements. The formulas are:

  • Rectangular: Length × Width × Average Depth × 7.5 = Gallons
  • Round: Diameter × Diameter × Average Depth × 5.9 = Gallons
  • Oval: Length × Width × Average Depth × 6.7 = Gallons
  • Kidney: Length × (Width A + Width B) × Average Depth × 3.38 = Gallons
What is average depth and how do I calculate it?

Average depth is the midpoint between the shallow end and deep end of your pool. Calculate it using this formula:

Average Depth = (Shallow End Depth + Deep End Depth) ÷ 2

For example, if your pool is 3 feet deep at the shallow end and 8 feet deep at the deep end, the average depth is (3 + 8) ÷ 2 = 5.5 feet.

How many gallons is a standard inground pool?

Standard inground pool sizes and their approximate volumes:

  • 12' x 24' x 5' avg depth: ~10,800 gallons
  • 16' x 32' x 5' avg depth: ~19,200 gallons
  • 18' x 36' x 5.5' avg depth: ~26,730 gallons
  • 20' x 40' x 6' avg depth: ~36,000 gallons
  • Round 24' x 4' depth: ~13,600 gallons
How much chlorine do I need for my pool?

For proper sanitation, maintain chlorine levels between 1-3 ppm (parts per million). A general rule is to add about 0.13 ounces of chlorine per 1,000 gallons of water to raise the level by 1 ppm. For shocking, use 2-4 times the normal amount depending on water condition.

Our calculator above provides chemical estimates based on your pool volume!

How often should I change my pool water?

Most pools don't need complete water changes. Instead, maintain proper chemical balance and filtration. However, you might need to drain and refill every 3-5 years due to:

  • High total dissolved solids (TDS)
  • Accumulated cyanuric acid (stabilizer)
  • Stubborn algae or staining
  • After major repairs
Does pool shape affect water volume calculation?

Yes, different pool shapes require different formulas because of their geometry:

  • Rectangular: Simple length × width × depth formula
  • Round: Uses π × radius² × depth
  • Oval: Uses an elliptical formula (π × length × width × depth ÷ 4)
  • Kidney: Uses a specialized formula accounting for the curved shape
What's the difference between gallons and liters?

Gallons and liters are both units of volume:

  • 1 US Gallon = 3.785 Liters
  • 1 Cubic Foot = 7.48 Gallons
  • 1 Cubic Meter = 1,000 Liters = 264 Gallons

Our calculator can display results in both units for your convenience!