Pool Volume Calculator
You may need to calculate the volume of your pool to determine how much water is needed to fill it up. Several formulas are available to help you do so, depending on the shape of your pool.
Basic Geometric Formulas for Pool Water Calculator
A pool circulation system consists of five major parts:
- Length (L)
- Width (W)
- Depth (D) or Height (H)
- Diameter (d) (for circular pools)
- Radius (r) (for circular pools)
- Pi (3.14 constant)
- Volume of a Square or Rectangular Pool (in feet): L x W x H
- Volume of a Circular Pool (in feet): Pi x r x r x H
Calculating Pool Volume in Square or Rectangular Pools
Multiply the depth of the pool by the surface area to calculate the volume in feet.
For more accurate results, divide the pool into various areas according to the depth. Measure from the depth of the water instead of the height of the pool wall.
Constant Depth Pools: Square or Rectangular
L x W x D = Volume (in feet)
Multiplying the pool’s length by width calculates its surface area. When multiplied by the depth, the result is the pool’s volume in feet.
For example, if the length of the pool is 200 feet, the width is 10 feet, and the depth is 6 feet, then the volume is 12,000 cubic feet:
200ft x 10ft x 6ft = 12,000 feet
Variable Depth Pools: Square and Rectangular
L x W x Average D = Volume (in feet)
Multiplying the pool’s length by width calculates its surface area. When multiplied by the average depth, the result is the pool’s volume in feet.
The formula to calculate the average depth is as follows:
(D at the shallow end + D at the deep end) / 2 = Average D
For example, if the shallow end is 4 feet and the deep end is 10 feet, and assuming the slope of the pool bottom is gradual and even, then the average depth is 7 feet:
Average depth = (4 + 10) / 2 = 7 feet
Pool Gallon Calculator
To calculate the pool volume in gallons, multiply your results above by 7.5 since there are 7.5 gallons per cubic foot.
To calculate the pool volume in liters, multiply your results above by 28.3168 since there are 28.3168 liters per cubic foot.
Calculating Pool Volume in Circular or Irregular Pools
3.14 x radius squared x Average D = Volume (in feet)
For example, if a pool’s diameter is 20 feet, half this value (the radius) is 10, and your depth is 4 feet, then the volume is 1,256 cubic feet:
3.14 x (10 x 10) x 4 = 1,256 cubic feet
Irregular Shaped Pools
If you have an oval, kidney shape, or other irregular shape pool, imagine your pool as a pairing of two smaller, regular shapes. Try envisioning smaller, separate squares, circles, or rectangles within the larger, irregular shape.
Use the appropriate formulas from above to calculate the volume of each shape. Then, add the results together to calculate the total capacity.