Pool Gallon Calculator

Calculate how many gallons are in your pool or pond

Pool Volume Formulas

Rectangular Pool: Length × Width × Average Depth × 7.5 = Gallons

Circular Pool: Diameter × Diameter × Average Depth × 5.9 = Gallons

Oval Pool: Long Diameter × Short Diameter × Average Depth × 6.7 = Gallons

Why Pool Volume Calculation Matters:

"Pool gallon calculator" and related terms like "pond calculator gallons" and "water volume calculator" are popular searches because:

  • Proper chemical treatment depends on accurate gallon measurements
  • Pump and filter sizing requires knowing your pool's volume
  • Water replacement calculations need precise gallon counts
  • Heating costs are directly related to water volume

Common Pool Sizes (Approximate Gallons):

Small Pool (12' x 24')

~8,600 gallons (4' average depth)

Large Pool (20' x 40')

~30,000 gallons (5' average depth)

Understanding Pool Volume Calculations

Accurately calculating your pool's water volume in gallons is essential for proper maintenance. Whether you're using a gallon calculator for your swimming pool, spa, or garden pond, knowing the exact volume helps with chemical dosing, equipment sizing, and water replacement.

Different Calculation Methods

Our water volume calculator supports three common shapes: rectangular, circular, and oval. Each shape requires slightly different formulas to convert dimensions to gallons. For irregular shapes, you may need to combine calculations or consult a professional.

Why Volume Matters

When searching for "how many gallons is my pool calculator," pool owners typically need this information for:

Beyond Pools: Other Uses

This tool also works as a pond calculator gallons tool for garden ponds, koi ponds, and water features. The same principles apply whether you're calculating volume for a small backyard pond or a large swimming pool.

Disclaimer

This pool gallon calculator provides estimates only. Actual pool volume may vary based on:

For professional pool services, chemical dosing, or equipment recommendations, please consult with a licensed pool professional. Always follow manufacturer instructions for all pool chemicals and equipment.

How Our Pool Gallon Calculator Works

Measure Your Pool

Accurately measure your pool's dimensions (length, width, diameter) and depths. Our tool works for rectangular, circular, and oval pools.

Enter Dimensions

Input your measurements into our gallon calculator. We automatically apply the correct formula based on your pool shape.

Get Accurate Results

Receive your pool's volume in gallons, plus surface area and average depth calculations to help with maintenance and equipment decisions.