Pool Volume Calculator
Find how many gallons or liters of water are needed to fill a swimming pool by selecting the pool shape and size below.
How to Calculate the Volume of a Rectangular Pool
The volume of a rectangular swimming pool in gallons can be found by multiplying length in feet × width in feet × average depth in feet × 7.48. The formula to find the volume is thus:
volume = length × width × depth × 7.48.
The first part of this formula determines the volume of water in cubic feet. The second part converts cubic feet to gallons, there are 7.48 gallons of water per ft3 of water.
Most pools have varying depths that slope from shallow to deeper. To accurately find the volume of water the average depth must be used. To find the average depth add the shallow depth with the deep depth then divide by 2, eg. (shallow + deep) ÷ 2.
How to Calculate the Volume of a Circular Pool
The volume of a circular swimming pool can be found by multiplying 3.14 times the radius in feet times the radius in feet times average depth in feet times 7.48. Thus, the formula is:
volume = πr2 × average depth × 7.48
The first part of this formula (πr2) determines the area and multiplying by the depth finds the volume. Multiplying by 7.48 finds the gallons of water per ft3 of water.
How to Calculate the Volume of an Oval Pool
The volume of an oval swimming pool can be found by multiplying the length in feet times the width in feet times 3.14 divided by 4 times average depth in feet times 7.48. The formula can be written like this:
volume = length × width × π ÷ 4 × depth × 7.48
The first part of this formula (length × width × π ÷ 4) determines the area and multiplying by the depth finds the volume. Again, multiplying by 7.48 determines how many gallons of water are in the pool.
Like a rectangular pool, the average depth can be found by adding the shallow and deep depths and then dividing by 2.
How to Calculate the Volume of an Irregular Oblong or Kidney Shaped Pool
The volume of a kidney shaped pool is a little more complicated. It can be found by multiplying the length in feet times (the shorter width in feet + the longer width in feet) times .45 times the average depth in feet times 7.48.
volume = length × (short width + the long width) × .45 × depth × 7.48
The first part (length × (short width+ long width) × .45) is used to find the area and then the volume is found by multiplying by the depth. Like before, multiplying by 7.48 finds the number of gallons in the pool.
Weights and Measures
To find the number of liters in a pool you can use our gallons to liters unit conversion calculator or multiply the gallons by 3.79.
To find the weight in pounds of the water in the pool you can multiply the number of gallons by 8.33, or use our water weight calculator.
One cubic foot of water is 12″ wide × 12″ long × 12″ deep and weighs 62.4 pounds.