How Many Gallons in a 16x32 Pool?
Water in the pool
17,236 gallons
Rectangle, 32 ft by 16 ft, shallow end 3 ft, deep end 6 ft, so the average depth is 4.5 ft.
Filling this pool on a garden hose takes 1.5 days of continuous water. Most water utilities sell a bulk fill, and some will not meter a pool fill through the sewer charge if you call first, which is worth more than the hose.
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How that number is worked out
These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.
- Pool shapeRectangle
- Length or diameter32 ft
- Width16 ft
- Shallow end depth3 ft
- Deep end depth6 ft
- Fill rate8 gal/min
- Turnover target8 hours
Water in the pool17,236 gallons
Filling this pool on a garden hose takes 1.5 days of continuous water. Most water utilities sell a bulk fill, and some will not meter a pool fill through the sewer charge if you call first, which is worth more than the hose.
| Surface area | 512 sq ftlength by width |
|---|---|
| Average depth | 4.5 ftmidpoint of shallow and deep |
| Volume | 2,304 cu ft7.48 gallons in each |
| Water weight | 71.9 tons143,741 lb |
| Fill time | 35.9 hoursat 8 gallons a minute |
| Pump for turnover | 35.9 gal/minwhole volume once in 8 hours |
| Heater to raise 10 degrees | 1,437,000 BTU8.34 BTU per gallon per degree |
| Liquid chlorine for a 10 ppm shock | 1.38 gal12.5 percent, sold in gallon jugs, so buy 2 |
| Salt to reach 3,200 ppm | 461 lb12 bags at 40 lb, from zero |
The material list this produces
| Water, gallons | 17,236 |
|---|---|
| Liquid chlorine 12.5 percent, gal | 2 |
| Salt, 40 lb bags | 12 |
| Pump, gal/min | 36 |
Deep end compared
The shallow end stays where this page has it and the deep end moves. Average depth is the midpoint of the two, so every foot you add at the deep end adds half a foot of average depth and the water goes up with it.
| Deep end | Water in the pool | Average depth | Pump for turnover |
|---|---|---|---|
| 4 ft | 13,406 gallons | 3.5 ft | 27.9 gal/min |
| 5 ft | 15,321 gallons | 4 ft | 31.9 gal/min |
| 6 ft | 17,236 gallons | 4.5 ft | 35.9 gal/min |
| 7 ft | 19,151 gallons | 5 ft | 39.9 gal/min |
| 8 ft | 21,066 gallons | 5.5 ft | 43.9 gal/min |
What else matters here
17,236 gallons. The 16 by 32 is the most common inground rectangle built and this is the volume nearly every rule of thumb in the pool trade was written around. When a product label says one bag per twenty thousand gallons, this is roughly the pool it is picturing.
512 square feet of surface, 72 tons of water, and 36 hours to fill on a hose. That last one is the number most new owners get wrong, because a day and a half of continuous water is enough that the utility should hear about it first. Many will credit the sewer portion of a measured pool fill, and none of them will do it after the fact.
The deep end is the only number on this page still up for negotiation, and the table below is the honest way to price it. Going from six feet to eight adds nearly four thousand gallons, which is everything downstream: more water, more chemical, more heating, a bigger pump for the same turnover, and a hole that costs more to dig and more to hold back.
What this calculator assumes
- A cubic foot of water is 7.48 gallons and a gallon weighs 8.34 pounds. Those two numbers do all the work on this page.
- Average depth is taken as the midpoint of the shallow and deep ends. That is exact for a pool with one straight slope between them and slightly generous for a pool with a flat shallow shelf and a hopper, which is the safer way for it to be wrong when you are buying chemicals.
- A round pool uses the diameter and ignores the width. An oval is figured as an ellipse, which is length times width times pi over four, not as a rectangle.
- Turnover is the time the pump takes to move the whole volume once. Eight hours is the common residential target and some health codes for public water are stricter, so check yours before you size a commercial pump off this.
- Liquid chlorine trade percent is defined so that one gallon of it raises ten thousand gallons of water by that many parts per million. One gallon of 12.5 percent raises 10,000 gallons by 12.5 ppm, which is where the dose row comes from rather than a chart.
- Salt is figured from zero to 3,200 ppm, which is the middle of the range most chlorine generators want. A pool that already has salt in it needs a test first, because salt only leaves with the water.
Questions people ask
How many gallons is a 16x32 with an 8 foot deep end?
21,066 gallons, against 17,236 with a six foot deep end. That is 3,830 more gallons, about twenty two percent, for two feet of depth at one end. The comparison table on this page works it at five, six, seven and eight so you can see the whole curve rather than one point on it.
Where does the chlorine dose come from?
Liquid chlorine trade percent is defined so that one gallon of it raises ten thousand gallons of water by that many parts per million. One gallon of 12.5 percent raises 10,000 gallons by 12.5 ppm. The row on this page is the gallons for a 10 ppm shock at that strength, worked from the volume rather than read off a chart, which is why it moves when you change the size.
What size pump does a 16x32 need?
17,236 gallons turned over once in eight hours is 36 gallons a minute, about 2,160 gallons an hour, and that is the flow the pump and the filter have to make together against the head in your plumbing. Set the turnover target to six hours on the calculator and it climbs to 48 gallons a minute, which shows what a shorter daily run actually costs in equipment.
The pool volume calculator takes any dimensions you like and hands back the same list.