A 27-foot round pool holds between 17,000 and 19,300 gallons of water.
A standard 27-foot round above-ground pool typically holds between 17,000 and 19,300 gallons of water depending on the total water depth. For a pool with 48-inch walls, the capacity is roughly 17,100 gallons. A 52-inch wall holds about 18,500 gallons, while a 54-inch wall holds approximately 19,250 gallons when filled to the proper level.
How to Calculate Water Volume
To determine the exact capacity of a round pool, you must use the mathematical formula for a cylinder. Follow these steps to calculate the volume in gallons:
- Measure the radius: For a 27-foot pool, the radius is 13.5 feet.
- Calculate surface area: Multiply the radius by itself and then by 3.14 (Pi).
- Determine average depth: Measure from the floor to the desired water line, not the top of the wall.
- Convert to gallons: Multiply the total cubic feet by 7.48 to find the total gallonage.
Comparison of Pool Filling Methods
| Filling Method | Estimated Duration | Relative Cost |
|---|---|---|
| Standard Garden Hose | 24 to 48 hours | Low (Utility Rates) |
| Bulk Water Delivery | 2 to 4 hours | High (Flat Fee) |
| Fire Hydrant Permit | 1 to 2 hours | Moderate (Permit Fee) |
Important Capacity Considerations
The total volume of water changes based on how much the pool is actually filled. Consider these factors when preparing for chemicals or maintenance:
- The 6-inch rule: Most pools are filled to approximately 6 inches below the top rail to accommodate the skimmer.
- Liners and Coves: Heavy foam coves at the base of the wall can slightly reduce the total volume by several hundred gallons.
- Water Displacement: Large groups of swimmers will displace water, but the total capacity remains the primary metric for chemical balancing.
Chemical and Filtration Requirements
Knowing the gallonage is essential for safe operation. For a 27-foot pool holding roughly 18,000 gallons, you should follow these guidelines:
- Shock Treatment: Use the volume to calculate the precise amount of chlorine or non-chlorine shock needed.
- Filtration Cycles: Ensure the pump can cycle the full 18,000 gallons at least once or twice every 24 hours.
- Water Balancing: Adjust pH, alkalinity, and calcium hardness based on the specific gallon measurement to prevent equipment damage.