Pool Gallon Calculator: Pool Volume Calculator (How Many?)

Pool Volume Calculator

Calculate the water volume of your swimming pool.









Results:

Enter values and press Calculate.

Knowing your pool’s water volume is essential for adding the right amount of chemicals, balancing pH levels, and ensuring proper filtration. Whether you have a round, oval, kidney-shaped, or irregularly shaped pool, using a Pool Gallon Calculator simplifies the process.

Instead of guessing, use the SilkySwim Pool Gallon Calculator to get an exact measurement of your pool’s water capacity—in both gallons and litres.


Why Use a Pool Gallon Calculator?

Adding too much or too little chlorine, pH balancers, or shock treatments can lead to water imbalances. Knowing how many gallons are in your pool ensures accurate chemical dosing and efficient filtration.

Avoid overusing chemicals and save money
Properly size your pool pump and filter
Ensure safety and comfort for swimmers
Calculate heating costs and water refills accurately

You can also download a pool gallon calculator PDF for easy offline reference when maintaining your pool.


How to Calculate Pool Volume in Gallons or Litres

The formula to calculate pool volume depends on the shape of your pool.

Rectangular or Square Pool Volume Calculation

🟦 Formula:
📏 Length × Width × Average Depth × 7.48 = Gallons

💧 Example:
A 20 ft × 10 ft pool with an average depth of 5 ft:
20 × 10 × 5 × 7.48 = 7,480 gallons

For litres, use Pool Volume Calculator Litres:
📏 Length × Width × Average Depth × 28.3 = Litres


Pool Gallon Calculator in Inches

If your pool depth is measured in inches, convert inches to feet first:

📏 1 inch = 0.0833 feet

Then, apply the standard volume formula:
📏 (Length × Width × Depth in feet) × 7.48 = Gallons

🔹 Example: If the depth is 60 inches (5 feet), convert first:
📏 (20 × 10 × 5) × 7.48 = 7,480 gallons


Pool Gallon Calculator for Oval Pools

An oval swimming pool gallon calculator uses a slightly different formula:

🟠 Formula:
📏 Length × Width × Average Depth × 5.9 = Gallons

💧 Example:
An oval pool measuring 30 ft × 15 ft with a 4-ft average depth:
30 × 15 × 4 × 5.9 = 10,620 gallons

For an above-ground oval pool gallon calculator, use the same formula.


Round Pool Volume Calculator

For circular pools, use:

⚫ Formula:
📏 Diameter × Diameter × Average Depth × 5.9 = Gallons

💧 Example:
A round pool with a 20 ft diameter and 4 ft depth:
20 × 20 × 4 × 5.9 = 9,440 gallons

This is useful for above-ground round pools like Intex pools.


Pool Volume Calculator for Irregular Shapes

If you have a freeform, kidney-shaped, or L-shaped pool, the best way to estimate volume is by breaking the pool into smaller sections and using the standard formulas for each shape.

🔹 Example:

  • A kidney-shaped pool gallon calculator may treat it as two circular sections combined.
  • An L-shaped pool gallon calculator will calculate each section separately and add the volumes.
  • A free-form pool gallon calculator may require professional measurement for accuracy.

For complex pool shapes, use the SilkySwim Pool Volume Calculator to simplify the process.


How Many Gallons in a Swimming Pool Olympic-Sized?

An Olympic swimming pool has standard dimensions of 164 ft × 82 ft × 6.5 ft.

Using the formula:
📏 164 × 82 × 6.5 × 7.48 = 660,430 gallons

For litres:
📏 164 × 82 × 6.5 × 28.3 = 2,500,000 litres

So, an Olympic-sized swimming pool holds approximately 660,000 gallons (2.5 million litres).


Tank Gallon Calculator for Pools & Water Tanks

If you’re storing pool water in a water tank, use a tank gallon calculator to measure capacity.

  • Rectangular Tanks: Use the same formula as rectangular pools
  • Cylindrical Tanks:
    📏 Diameter × Diameter × Height × 5.9 = Gallons

This helps determine how much water you need for filling or draining your pool.


Pool Gallon Calculator for In-Ground & Above-Ground Pools

Whether you have an in-ground or above-ground pool, use the appropriate pool gallon calculator:

In-ground pool gallon calculator – Ideal for permanent pools
Above-ground oval pool gallon calculator – Works for oval-shaped portable pools
Intex pool gallon calculator – For Intex brand above-ground pools
Pentair pool gallon calculator – Often used with Pentair pool equipment

For best results, use an online calculator like the SilkySwim Pool Gallon Calculator.


Final Thoughts: Use a Pool Gallon Calculator for Precision

Calculating your pool’s volume is essential for maintaining proper chemical balance, filtration, and heating efficiency. Instead of estimating, use a Pool Gallon Calculator to get accurate results.

Quick Recap:

✔ Use the SilkySwim Pool Gallon Calculator for quick, accurate results.
✔ Need litres? Try a pool gallon calculator in litres.
✔ Have an irregular pool shape? Use a pool volume calculator irregular shape.
✔ Want an Olympic pool estimate? It holds 660,000 gallons (2.5 million litres).
✔ Measuring Intex, Pentair, or above-ground pools? Use a specialized pool gallon calculator.

Take the guesswork out of pool maintenance—use a pool gallon calculator today!