From backyardcity:
If you have a 12 ft round with 48 inch tall walls, your pool would hold approximately 2,975 gallons.
If you have a 12 ft round with 52 inch tall walls, your pool would hold approximately 3,398 gallons.
These are the standard sizes so I bet your pool is one of those sizes.
3,398.4 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.
How much water in a 48inch 12foot round pool
None if it's a hole, 1570.8 if it's full of water.
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.
13,594 US gallons of water.
This pool can hold a maximum of about 5,707.6 gallons of water.
5,287.7 gallons of water.