A 21' pool that is 48" high should have 10,407 gallons of water (approx). To calculate the gallons in a round swimming pool use this formula: Length x length x average depth x 5.9 = gallons of pool So in your case 21 x 21 x 4 x 5.9 = 10,407 gallons
Assuming 21 feet is the diameter, the volume of your pool is pir2h 3.14159 x (10.5)2 x 4 3.14159 x 110.25 x 4 1385.4424 feet3 Now we must convert feet cubed to gallons. 1385.4424 cubic feet = 10,636.828 gallons. That will fill your pool!
Pi x r squared x depth x 7.481 (gallons per cubic foot) 3.14 x 10.5 x 10.5 x 4 x 7.481 = 10,359 gallons
The volume of the pool is 1385.45 cu ft for a maximum capacity of 10,364.5 gallons of water.
This pool can hold a maximum of 9,400 gallons of water.
10,408 gallons.
11,709 US gallons of water.
1.74 gallons
Length x width x average depth x 5.9 gallons per cubic foot (that is the factor used in round pools) = 3,398 US Gallons.
A 2-foot round pool with 12 inches of water is holding about 23.6 gallons of water.
489.76 gallons of water.
141.06 gallons
Alittle under 10,000 gallons.
A round pool that is 16 feet across and is filled with 48 inches of water will contain about 6,041 gallons of water.
This pool can hold up to 1,689.7 gallons of water.
This pool can hold a maximum of about 5,707.6 gallons of water.
5,287.7 gallons of water.
13,594 US gallons of water.
This pool, when filled with 4.5 feet of water, will contain about 15,300 gallons of water.
6,200 gallons.