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Pool Volume Calculator

How much water does your swimming pool hold?
Use our pool volume calculator to quickly find out by choosing your pool's shape, dimensions, and depth.

Select Pool Shape:

Rectangle Pool Volume Formula

Calculating Pool Volume Essentials:

To determine the volume of your pool, you'll need to compute the surface area and average depth of your pool. This requires a few fundamental measurements:

  • Length (L)
  • Width (W)
  • Depth (D) or Height (H)
  • Diameter (d) (for circular pools)
  • Radius (r) (for circular pools)
  • The constant Pi (π ≈ 3.14)

For a rectangular pool, you can find the surface area by multiplying the length and width. When you include the depth (or height), you can perform a basic volume calculation.

Another critical element in this calculation is the fact that one cubic foot of water holds approximately 7.5 gallons. To determine the total gallons your pool can hold, simply multiply your final cubic foot measurement by 7.5.

Common Pool Sizes

Check the average gallons that the most common pool sizes and shapes hold for in-ground and above-ground pools.

Common Above-Ground Pool Sizes
48" Wall Height 52" Wall Height
Pool Size Gallons Gallons
15' Round 5,300 5,800
18' Round 7,600 8,300
20' Round 9,400 10,200
24' Round 13,600 15,300
27' Round 17,200 18,600
28' Round 18,500 20,000
11x25 Oval 6,500 7,000
15x25 Oval 7,800 8,400
15x30 Oval 8,900 9,600
18x33 Oval 10,600 11,500
18x38 Oval 14,000 15,200
Common Inground Pool Sizes
Average Wall Height
Pool Size Gallons
12x24 Rectangular 10,800
16x32 Rectangular 19,200
16x36 Rectangular 21,600
18x36 Rectangular 24,300
20x40 Rectangular 30,000
16x32 Oval 17,000
18x36 Oval 21,700
20x40 Oval 26,800
17x33 Grecian 19,700
17x37 Grecian 22,200
20x36 Grecian 24,300
20x44 Grecian 30,300
16x30 Kidney 14,900
16x34 Kidney 16,500
20x38 Kidney 20,200

How to Calculate Pool Volume Step-By-Step

  1. How to Calculate Gallons For Rectangle or Square Pool:
    1. Step 1: Gather Information
      • Measure the length (L), width (W), and average depth (D) of your rectangular pool in feet.
    2. Step 2: Calculate Volume
      • To find the volume in cubic feet, use the formula: Volume = Length (L) x Width (W) x Average Depth (D).
      • Multiply the values of L, W, and D together to get the volume in cubic feet.
    3. Step 3: Convert to Gallons
      • To convert cubic feet to gallons, multiply the cubic feet value by 7.48052 (since 1 cubic foot is approximately equal to 7.48052 gallons).
      • Volume (gallons) = Volume (cubic feet) x 7.48052.
  2. How to Calculate Gallons For Kidney Pool:
    1. Step 1: Gather Information
      • Measure the lengths of sides A (LA) and B (LB), length of side C (LC), shallow depth (DS), and deep depth (DD) of your kidney-shaped pool in feet.
    2. Step 2: Calculate Volume
      • To find the volume in cubic feet, use the formula: Volume = 0.45 x (LA + LB) x LC x (DS + DD).
      • Multiply the values according to the formula to get the volume in cubic feet.
    3. Step 3: Convert to Gallons
      • Convert cubic feet to gallons by multiplying the cubic feet value by 7.48052.
      • Volume (gallons) = Volume (cubic feet) x 7.48052.
  3. How to Calculate Gallons For Circle Pool:
    1. Step 1: Gather Information
      • Measure the diameter (D) and depth (D) of your circular pool in feet.
    2. Step 2: Calculate Volume
      • To find the volume in cubic feet, use the formula: Volume = π x (D/2)^2 x Depth (D).
      • Square the radius (D/2), multiply it by π (approximately 3.14159), and then multiply by the depth to get the volume in cubic feet.
    3. Step 3: Convert to Gallons
      • Convert cubic feet to gallons by multiplying the cubic feet value by 7.48052.
      • Volume (gallons) = Volume (cubic feet) x 7.48052.

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