Knowing your pool’s volume in gallons is important to many facets of pool maintenance. For example, knowing your pool’s volume in gallons helps you calculate correct dosages for chemical treatments, filtration cycles, and sizing of pool equipment. In this article, we show you how to calculate your pool’s gallonage, as well as an easy reference chart for your pool.

The formulas used for calculating your pool’s volume in gallons are based on this Length (ft) x Width (ft) x Constant x Depth (ft). Round and oval pools use a constant of 5.9 and rectangular calculations use 7.5; see below examples.

12′ Round w/48″ Wall A/G Pool: 12 x 12 x 5.9 x 3.5 = 2,794 gallons

12′ x 24′ Oval w/52″ Wall A/ G Pool: 12 x 17 x 5.9 x 3.83 = 5,608 gallons

20′ x 40′ Rectangle, 5′ Average Depth Inground Pool: 20 x 40 x 7.5 x 5 = 30,000 gallons

For above ground pools, we assume the actual fill depth is 6-inches below wall height. We account for that by substituting 3.5 for 48″ wall, 3.83 for 52″ wall, and 4 for 54″ wall. The average depth for inground pools is calculated by averaging the shallow and deep end depths. For example, a 3-foot shallow end with a 7-foot deep end average to 5 feet.

Round A/G Pool Volume Chart

Round Pool Size	48" Wall*	52" Wall*	54" Wall*
12'	2,974	3,254	3,398
15'	4,646	5,084	5,310
16'	5,286	5,785	6,042
18'	6,691	7,321	7,646
20'	8,260	9,039	9,440
21'	9,107	9,965	10,408
24'	11,894	13,016	13,594
27'	15,054	16,473	17,204
28'	16,190	17,716	18,502
30'	18,585	20,337	21,240
33'	22,488	24,608	25,700
36'	26,762	29,286	30,586
*Assumes Pool’s Fill Depth Is 6” Below Wall Height

Oval A/G Pool Volume Chart

Oval Pool Size	48" Wall*	52" Wall*	54" Wall*
12'x17'	4,213	4,610	4,814
12'x20'	4,956	5,423	5,664
12'x24'	5,947	6,508	6,797
15'x24'	7,434	8,135	8,496
15'x25'	7,744	8,474	8,850
15'x26'	8,054	8,813	9,204
15'x27'	8,363	9,152	9,558
15'x30'	9,293	10,169	10,620
15'x33'	10,222	11,186	11,682
16'x24'	7,930	8,677	9,062
16'x32'	10,573	11,570	12,083
18'x33'	12,266	13,423	14,018
18'x44'	16,355	17,897	18,691
21'x43'	18,647	20,405	21,311
*Assumes Pool’s Fill Depth Is 6” Below Wall Height

Rectangle Inground Pool Volume Chart

Inground Pool Size	3.5'	4'	4.5'	5'
12'x24'	7,560	8,640	9,720	10,800
14'x28'	10,290	11,760	13,230	14,700
16'x32'	13,440	15,360	17,280	19,200
16'x36'	15,120	17,280	19,440	21,600
18'x36'	17,010	19,440	21,870	24,300
20'x40'	21,000	24,000	27,000	30,000
20'x44'	23,100	26,400	29,700	33,000
24'x40'	25,200	28,800	32,400	36,000
25'x45'	29,531	33,50	37,949	42,188
25'x50'	32,813	37,500	42,188	46,876
30'x50'	39,375	45,000	50,625	56,250
30'x60'	47,250	54,000	60,750	67,500

Do you have any questions about your pool size? Leave a comment down below and we’d be happy to answer you.