Before you can start any kind of chemical treatment of your pool water, you will need to know how many gallons are in your pool. There is a simple way to calculate your pool volume that only requires 4 basic numbers:
 The length of your pool
 the width of your pool
 The average depth
 the multiplier factor
The formula is LENGTH x WIDTH x AVERAGE DEPTH x MULTIPLIER = The number of gallons in your pool!
length and width are easy measurements that you get with a tape measure. For round pools the “length and width” will be the same and is just calculated as the longest measurement you can get going from one side to the other.
Multiplier is just a factor that depends on the shape of your pool. A rectangle, square or free form pool has a multiplier of 7.5 . A round or oval pool has a multiplier of 5.9
Average depth is just what is says.The average depth of your pool. Take the deepest point plus the shallowest point. Add them together and devide by two. ( For example : shallow end 3′ deepest end 9′ = 12′ feet combined devided by 2 = 6′ average depth ) For above ground pools take 4″ off of the height of the sidewall ( so a 52″ pool has 48″ of water. A 48″ pool has 44″, etc ).
Example: a 10′ x 20′ rectangle pool with an average depth of 6′ would calculate the water volume as follows: 10 x 20 x 6 x 7.5 = 9,000 gallons !
The charts bellow show the water content of standard round and oval above ground pools, as well as some common size in ground pools. Once you have determined your pool volume, Click pool chemicals to see the eFamilyFun solutions for a perfect sparkeling pool!
Above ground pool 48″ wall


12 ft Round  ~2,975 gallons  12′ x 24′ Oval  ~ 5,948 gallons 
15 ft Round  ~4,646 gallons  15′ x 30′ Oval  ~ 9,293 gallons 
18 ft Round  ~ 7,646 gallons  16′ x 32′ Oval  ~ 10,573 gallons 
21 ft Round  ~ 9,106 gallons  18′ x 33′ Oval  ~ 12,267 gallons 
24 ft Round  ~ 11,895 gallons  
27 ft Round  ~ 15,054 gallons  
30 ft Round  ~ 18,585 gallons  
33 ft Round  ~ 22,488 gallons 
Above ground pool 52″ wall


12 ft Round  ~ 3,398 gallons  12′ x 24′ Oval  ~ 6,797 gallons 
15 ft Round  ~ 5,310 gallons  15′ x 30′ Oval  ~ 10,620 gallons 
18 ft Round  ~ 8,602 gallons  16′ x 32′ Oval  ~ 12,084 gallons 
21 ft Round  ~ 10,408 gallons  18′ x 33′ Oval  ~ 14,019 gallons 
24 ft Round  ~ 13,594 gallons  18′ x 40′ Oval  ~ 19,116 gallons 
27 ft Round  ~ 17,205 gallons  
30 ft Round  ~ 21,240 gallons  
33 ft Round  ~ 25,700 gallons 
In ground Pools


POOL SIZE  GALLON 3.5′ Av. DEPTH  GALLON 4′ Av. DEPTH  GALLON 4.5′ Av. DEPTH  GALLON 5′ Av. DEPTH  GALLON 5.5′ Av. DEPTH 
12′ x 24′  7,600  8,600  9,700  10,800  11,900 
14′ x 28′  10,300  11,800  13,200  14,700  16,200 
15′ x 30′  11,800  13,500  15,200  16,900  18,600 
16′ x 32′  13,400  15,400  17,300  19,200  21,100 
18′ x 36′  17,000  19,400  21,900  24,300  26,700 
19′ x 38′  19,000  21,700  24,400  27,100  29,800 
20′ x 40′  21,000  24,000  27,000  30,000  33,000 
22′ x 44′  25,400  29,000  32,700  36,300  39,900 
25′ x 45′  29,531  33,750  37,968  42,187  46,406 
25′ x 50′  32,800  37,500  42,200  46,900  51,600 
30′ x 50′  39,375  45,000  50,525  56,250  61,875 