Pool Volume Calculator
Determine the total water capacity of your pool in gallons using standard geometric dimensions.
Pool Size & Shape
Salinity & Brand Settings
YOUR RESULTS
Pour salt around the shallow end perimeter. Brush with a pool brush until completely dissolved before turning on the Salt Chlorine Generator (SWCG).
IDEAL SALT POOL CHEMISTRY
Understanding the Geometry of Pool Water Capacity
Calculating pool volume is not just useful for adding chemicals; it is also crucial for sizing pool filters, pool pumps, and pool heaters. A pool pump must be capable of cycling the entire volume of water at least once every 8 hours (referred to as a turnover cycle).
The volume depends entirely on three-dimensional geometry. We break this down into surface area (determined by shape dimensions) and average depth.
Volumetric Multipliers Explained
A single cubic foot of space contains exactly **7.48 gallons** of water. When calculating capacity, we use multipliers that simplify the conversion from cubic feet directly into gallons:
- Rectangular Pools: Because the corners are exact right angles, we multiply Length × Width × Average Depth by **7.5**.
- Round Pools: We calculate the area of the circle using $\pi r^2$, multiply by Average Depth, and multiply by **7.5**.
- Oval Pools: To account for the rounded ends of an oval shape, we adjust the volumetric multiplier to **5.9** (Length × Width × Average Depth × 5.9).
Why We Offer a Volume Override
If your pool was built professionally, the structural specifications doc or your builder's blueprints will declare the exact water volume capacity. In this case, measuring and entering dimensions can lead to rounding errors. Use our **"I already know my pool volume"** override toggle in the calculator to enter your exact gallons value directly and get precise salt/shock dosages instantly.
Volume FAQs
Why is knowing pool volume critical for pool maintenance?
Every chemical dosage, filtration cycle, and heater requirement is directly proportional to your pool's total water volume in gallons. Underestimating volume leads to chemical under-dosage and algae; overestimating can cause toxic chemical levels and damage pool equipment.
How do I calculate the volume of a kidney-shaped pool?
Kidney-shaped pools are calculated using a modified oval formula. Measure the length, the width of the larger lobe (A), and the width of the smaller lobe (B). The formula is: (A + B) × Length × Average Depth × 0.45 × 7.48. You can also use our manual volume override to input the volume if provided by your builder.
How does pool shape change the volume multiplier?
The volumetric multiplier translates cubic capacity (cubic feet) into gallons. A cubic foot holds approximately 7.48 gallons. For rectangles, the multiplier is 7.5. For ovals, it is adjusted to 5.9 to account for curved corners. For circular pools, the standard $\pi \times \text{Radius}^2$ formula is scaled directly.