When calculating your pool’s volume, it’s essential to measure from the water’s surface depth—not the height of the wall or the total depth of the pool. You need to know how much water is actually in your pool, and it’s likely not filled to the very top.
The Basics of Pool Volume Calculation
To calculate your pool’s volume, you’ll need to determine both the surface area and the average depth. Here’s what you’ll need to measure:
- Length (L)
- Width (W)
- Depth (D) or Height (H)
- Diameter (d) for round pools
- Radius (r) for round pools
- Pi (3.14 constant)
Start by multiplying the length and width to get the surface area of a rectangular pool. Then, add the average depth to this number for a basic volume calculation.
Another key point: One cubic foot of water equals 7.5 gallons. So, after calculating the volume in cubic feet, multiply that figure by 7.5 to find out how many gallons of water your pool holds.
Calculating Rectangular Pool Volume
How you calculate volume for a rectangular pool depends on the pool’s bottom layout.
Constant Depth Pools
For pools with a constant depth (no shallow or deep end), use this formula:
L × W × D × 7.5 = V (in gallons)
For example, if your pool is 32 feet long, 16 feet wide, and 4 feet deep:
- 32 × 16 × 4 × 7.5 = 15,360 gallons
Variable Depth Pools with a Gradual Slope
For rectangular pools with varying depths, such as a shallow and deep end, you’ll first need to calculate the pool’s average depth. Add the shallow end depth and deep end depth together, then divide by 2 to find the average depth.
For example, if the shallow end is 3 feet and the deep end is 9 feet, the average depth is 6 feet.
Then, multiply the pool’s length, width, and average depth. Finally, multiply that result by 7.5 to get the pool’s volume in gallons.
For instance, for a pool that is 32 feet long, 16 feet wide, and has an average depth of 6 feet:
- 32 × 16 × 6 × 7.5 = 23,040 gallons
Variable Depth Pools with a Drop-Off
If your pool has a sharp drop-off between the shallow and deep ends, you’ll need to treat each section of the pool as separate parts. Calculate the volume for each section using the constant depth formula, then add them together for the total volume.
Irregular-Shaped Pool Volume
For pools with irregular shapes, such as oval or kidney-shaped, the process becomes a little more complex. Break the pool down into smaller, regularly shaped sections—like squares, rectangles, or circles. Measure each section and apply the same formulas mentioned above to calculate the volume of each part. Then, add the volumes of each section together for an approximate total volume.
When to Seek Professional Help
If you have an unusual pool shape or want more precise calculations, it’s a good idea to consult a professional. They can take accurate measurements and provide a more exact volume estimate. Knowing your pool’s volume is essential, especially when adding chemicals to your pool water. It ensures you’re adding the right amount of chemicals and is crucial when installing a new pool pump, filter, or heater.
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Written by the Digital Marketing Team at Creative Programs & Systems: https://www.cpsmi.com/.