Swimming Pool Water Volume Calculator & Charts

Swimming Pool Water Volume Calculator & Charts

How to calculate the Water Volume of a Swimming Pool using Charts or a Calculator



Why do you need to know you Pool's Water Volume?

In order to figure out proper doses of chemicals for your pool, you need to accurately determine how many gallons of water it holds.  To do that, you need to know four different numbers: the length, width, average depth, and a multiplier for your type of pool.

Here is the pool volume formula:

Length x Width x Average Depth x Multiplier = Volume in US Gallons

Determine the Multiplier:

  • Multiplier = 7.5 for Rectangle, Square, or Free-Form pools
  • Multiplier = 5.9 for Round or Oval pools

Determine the Average Depth:

To determine the average depth in a pool where the bottom slopes, measure the shallow end, the deep end depth. Add them together and divide by two (2).

Example:

Shallow End = 2ft. Deep End = 10ft
2ft + 10ft = 12ft; 12/2 = 6ft average depth

Standard In-Ground Pool Volumes in Gallons by Size
Pool Size
(in feet)
3.5 ft
Avg Depth
4 ft
Avg Depth
4.5 ft
Avg Depth
5 ft
Avg Depth
12x24 7,600 8,600 9,700 10,800
14x28 10,300 11,800 13,200 14,700
15x30 11,800 13,500 15,200 16,900
16x32 13,400 15,400 17,300 19,200
18x36 17,000 19,400 21,900 24,300
19x38 19,000 21,700 24,400 27,100
20x40 21,000 24,000 27,000 30,000
22x44 25,400 29,000 32,700 36,300
25x45 29,531 33,750 37,968 42,187
25x50 32,800 37,500 42,200 46,900
30x50 39,375 45,000 50,525 56,250


Use this Pool Volume Calculator!!

(works with Square, Rectangle, Grecian, Roman
& is a good approximation for Ovals & Freeform pools)
Length in feet
Width in feet
Depth (deep end)
Depth (shallow end)
Approximate US gallons
Approximate UK gallons


Above Ground Swimming Pool Water Volumes by Size
Size 48in Wall* 52in Wall*
12ft Round 2,975 gals 3,398 gals
15ft Round 4,646 gals 5,310 gals
18ft Round 7,646 gals 8,602 gals
21ft Round 9,106 gals 10,408 gals
24ft Round 11,895 gals 13,594 gals
27ft Round 15,054 gals 17,205 gals
30ft Round 18,585 gals 21,240 gals
33ft Round 22,488 gals 25,700 gals
12x24ft Oval 5,948 gals 6,797 gals
15x30ft Oval 9,293 gals 10,620 gals
16x32ft Oval 10,573 gals 12,084 gals
18x33ft Oval 12,267 gals 14,019 gals
* Assumes water depth is 6 inches less than wall height


Round Swimming Pool Volume Calculator

Diameter in Feet
Depth (deep end) in Feet
Depth (shallow end) in Feet

Approximate US gallons
Approximate UK Gallons



Last Updated: 02/16/2024 12:03 PM - ID:1694