Use our free pool volume calculator to determine exactly how many gallons or litres your swimming pool holds. Works for rectangular, round, oval, and irregular pool shapes.
Quick Reference
Knowing your pool volume is essential for chemical dosing, pump sizing, heating costs, and water balance. Most residential pools hold between 15,000โ25,000 gallons.
Why Pool Volume Matters
Knowing your pool's exact volume is critical for:
- Chemical dosing: All pool chemicals (chlorine, acid, salt, alkalinity products) are dosed based on gallons.
- Pump and filter sizing: Equipment must be sized to handle your pool's volume efficiently.
- Heating costs: Larger pools require more energy to heat.
- Water balance: LSI calculations need accurate volume for proper balance.
- Cost estimation: Water refill costs and chemical budgets depend on volume.
How to Use This Pool Volume Calculator
Select your pool shape and enter the required dimensions. The calculator will instantly determine:
- Total volume in gallons and litres.
- Water weight in pounds and kilograms.
- Estimated chemical doses for common pool chemicals.
๐ก Pro Tip
For the most accurate volume, measure your pool's dimensions carefully. For irregular shapes, break the pool into sections, calculate each section's volume, and add them together.
Understanding Pool Volume Formulas
Each pool shape uses a different formula to calculate volume. Here's how it works:
๐ Rectangle
Length ร Width ร Depth ร 7.48052
For 32' ร 16' ร 5' = 1,915 gallons
โญ Round
ฯ ร (Radius)ยฒ ร Depth ร 7.48052
For 24' diameter ร 5' = 16,957 gallons
๐ฅ Oval
ฯ ร (Length/2) ร (Width/2) ร Depth ร 7.48052
For 32' ร 18' ร 5' = 16,904 gallons
๐ Irregular
Surface Area ร Depth ร 7.48052
For 500 ftยฒ ร 5' = 18,701 gallons
How to Measure Your Pool
For accurate volume calculation, follow these measurement tips:
- Length and Width: Measure at the waterline (not the coping). For irregular shapes, take multiple measurements.
- Depth: Measure at the deepest point and the shallowest point. Average depth = (deep + shallow) รท 2.
- Kidney Shape: Measure length, widest width, and narrowest width. Use the average width (widest + narrowest รท 2).
- Freeform: Break into sections (rectangles, triangles, circles) and calculate each section's volume, then add them together.
๐ Pro Tip
If you have a pool design plan or blueprint, you can find exact dimensions there. For existing pools, use a measuring tape and take measurements at multiple points to ensure accuracy.
Frequently Asked Questions
Why is pool volume important?
Pool volume is essential for accurate chemical dosing, equipment sizing, and water balance calculations. Adding too much or too little chemical can harm swimmers, damage equipment, and waste money.
How accurate is this calculator?
This calculator provides a close estimate based on standard formulas. For exact volume, consider professional measurement or water meter readings when filling the pool.
What if my pool has a sloped floor?
Use the average depth method: measure the deepest point and shallowest point, add them together, and divide by 2. For more accuracy, measure depth at multiple points and average them.
How much does pool water weigh?
One gallon of water weighs approximately 8.34 pounds. A 20,000-gallon pool contains about 166,800 pounds (83.4 tons) of water.
Need Professional Help?
If you're unsure about your pool's volume, or if you need help with chemical dosing or equipment sizing, our team of pool service experts is here to help. We provide professional pool maintenance, water testing, and equipment installation services nationwide.