Pool Gallon Calculator

Calculate the volume of your pool to ensure proper chemical treatment.

Pool Details

Your Pool's Volume

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Gallons

This is an estimate for informational purposes. Actual volume may vary.

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About the Pool Gallon Calculator

This calculator helps pool owners determine the volume of water in their pool, measured in gallons or liters. Knowing your pool's volume is the most critical step for proper maintenance, as it allows you to add the correct amount of chemicals like chlorine, shock, and algaecide to keep your water safe and clean.

Formula Explained

The calculator first finds the volume in cubic feet (or meters) and then converts it to gallons (or liters) using standard conversion factors.

  • Rectangle: Length × Width × Average Depth
  • Round: π × (Radius)² × Average Depth
  • Oval: Length × Width × 0.89 × Average Depth
  • Kidney: (Width A + Width B) × Length × 0.45 × Average Depth

Conversion factors used: 1 cubic foot = 7.48 US gallons, 1 cubic meter = 1,000 liters.

How to Get Better Results

For the most accurate volume calculation, follow these tips:

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Measure the Water Line

Measure the actual length and width of the water, not the pool's coping or edge, for the most accurate surface area.

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Calculate Average Depth

For pools with a sloped bottom, measure the depth at the shallowest and deepest points, add them together, and divide by two.

Frequently Asked Questions

How do you calculate the volume of a pool in gallons?

To calculate the volume of a pool, you first find its volume in cubic feet using a formula based on its shape (e.g., Length × Width × Average Depth for a rectangle). Then, you multiply the cubic feet by a conversion factor of 7.48 to get the total volume in U.S. gallons. Our calculator handles all these conversions for you.

How do I find the average depth of my pool?

If your pool has a sloped bottom, you need to find the average depth for an accurate volume calculation. Measure the depth of the shallow end and the depth of the deep end. Add these two numbers together and then divide by 2. The result is your average depth. For example, if the shallow end is 3 feet and the deep end is 8 feet, the average depth is (3 + 8) / 2 = 5.5 feet.

Why is knowing my pool's volume important?

Knowing your pool's exact volume is crucial for proper maintenance and safety. All chemical treatments, such as chlorine, algaecide, and pH balancers, are dosed based on the amount of water in the pool. Adding too little can be ineffective, while adding too much can be dangerous for swimmers and damage your pool equipment.

How do you calculate the volume of a kidney-shaped pool?

Calculating the volume of a kidney-shaped pool is more complex. A common formula is: Volume = (Width A + Width B) × Length × 0.45 × Average Depth. 'Width A' and 'Width B' refer to the widest points of the two rounded ends of the pool. The 0.45 is a constant multiplier used to approximate the irregular shape.

How many gallons are in a typical backyard pool?

The volume of a backyard pool can vary greatly. A small, round above-ground pool might hold 4,000 to 5,000 gallons. A medium-sized rectangular in-ground pool (e.g., 15 ft x 30 ft) typically holds between 15,000 and 20,000 gallons. Larger pools can easily exceed 30,000 gallons.