Expert Verified Updated: March 2026

Pool Water Weight Calculator

Structural safety starts with accurate numbers. Calculate the total weight and pressure of your pool water for decks, slabs, and foundations.

Quick Conclusion
Water weighs 8.34 lbs per gallon. A standard 20,000-gallon pool weighs approximately 166,800 lbs (83.4 tons). If you are placing a pool on a deck, you must consider both the "Static Load" of the water and the "Dynamic Load" of people jumping and splashing.

Technical Comparison

Volume (Gal) Weight (Lbs) Weight (Short Tons)
5,000 Gal 41,700 Lbs 20.8 Tons
15,000 Gal 125,100 Lbs 62.5 Tons
25,000 Gal 208,500 Lbs 104.2 Tons

Actionable Steps

Pro-Tip

The "Jump" Factor: Structural engineers use a "Safety Factor" of 1.5x minimum. Why? Because when a 200lb person jumps into the water, the instantaneous force (Dynamic Load) on the floor of the pool is much higher than their body weight. Always build for the peak load, not the average.

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