Pool Water Volume Calculator
Estimate gallons for rectangular, round, oval, and irregular pools
(shallow + deep) รท 2
๐ Total Pool Water Volume
โ
โ liters
โ cubic meters
โ ๏ธ Disclaimer: Always consult a structural engineer for load-bearing elements. This tool provides estimates only. For irregular pools, measure carefully and consider professional consultation.
๐ How to Use This Pool Water Volume Calculator (Step-by-Step)
Follow these steps to get an accurate estimate of your pool’s water volume:
- Select your pool shape โ Rectangular, Round, Oval, or Irregular (kidney/lazy L).
- Enter dimensions โ Length, width, diameter, or average width as needed.
- Enter depth โ For flat-bottom pools, use the uniform depth. For sloped pools, enter shallow and deep ends (average is auto-calculated).
- Click “Calculate Water Volume” โ The tool instantly shows gallons, liters, and cubic meters.
- Use for chemical treatment โ Accurate volume is essential for proper chlorine, pH balancers, and algaecide dosing.
Pro tip: For irregular-shaped pools (kidney, figure-8, lazy L), measure the length and estimate the average width at several points, then average them.
๐๏ธ Real-World Pool Volume Examples
Example 1: Standard Rectangular Pool (40′ x 20′ x 5′ avg depth)
Formula: Length ร Width ร Avg Depth ร 7.48052
Calculation: 40 ร 20 ร 5 = 4,000 cu ft ร 7.48052 = 29,922 gallons
Formula: Length ร Width ร Avg Depth ร 7.48052
Calculation: 40 ร 20 ร 5 = 4,000 cu ft ร 7.48052 = 29,922 gallons
Example 2: Sloped Rectangular Pool (40′ x 20′, shallow 3′, deep 8′)
Avg Depth: (3 + 8) รท 2 = 5.5 ft
Volume: 40 ร 20 ร 5.5 ร 7.48052 = 32,914 gallons
Avg Depth: (3 + 8) รท 2 = 5.5 ft
Volume: 40 ร 20 ร 5.5 ร 7.48052 = 32,914 gallons
Example 3: Round Pool (24′ diameter x 4.5′ depth)
Formula: ฯ ร (Diameter/2)ยฒ ร Depth ร 7.48052
Calculation: 3.1416 ร (12)ยฒ ร 4.5 = 2,035 cu ft ร 7.48052 = 15,223 gallons
Formula: ฯ ร (Diameter/2)ยฒ ร Depth ร 7.48052
Calculation: 3.1416 ร (12)ยฒ ร 4.5 = 2,035 cu ft ร 7.48052 = 15,223 gallons
Example 4: Oval Pool (30′ x 15′ x 4.5′ avg depth)
Formula: Length ร Width ร Depth ร 5.9 (oval factor)
Calculation: 30 ร 15 ร 4.5 ร 5.9 = 11,948 gallons
Formula: Length ร Width ร Depth ร 5.9 (oval factor)
Calculation: 30 ร 15 ร 4.5 ร 5.9 = 11,948 gallons
โ Frequently Asked Questions
How many gallons are in an Olympic swimming pool?
An Olympic pool (50m x 25m x 2m) holds approximately 660,000 gallons (2.5 million liters).
How do I calculate average depth for a sloped pool?
Add the shallow end depth to the deep end depth, then divide by 2. Example: 3ft shallow + 8ft deep = 11 รท 2 = 5.5ft average depth.
Why is my pool volume important?
Accurate volume is critical for: chemical dosing (chlorine, pH balancers), pump sizing, heater sizing, and water treatment costs.
How much water does a typical residential pool hold?
Most residential pools range from 10,000 to 30,000 gallons. Small plunge pools: 3,000-8,000 gallons. Large custom pools: 40,000+ gallons.
How do I measure an irregular (kidney) shaped pool?
Measure the longest length. Then measure width at several points (every 5-10 feet), average those widths, then use Length ร Avg Width ร Avg Depth ร 7.48.
How much does it cost to fill a pool?
Water costs vary by location ($2-10 per 1,000 gallons). A 20,000 gallon pool costs $40-200 to fill. Some municipalities offer pool-filling discounts.
