Potable Water / Hydronic Expansion Tank Sizing Calculator

1. Water Heater / Boiler Total Water Capacity (Gallons)


2. Supply Line Pressure


3. Air Pre-Charge (Tank Pre-charge should equal supply line pressure)


4. Relief Valve


5. Start temperature


6. Ending Temperature


Click the button below to determine the total volume required.

Minimum Acceptance Volume  (Gallons) (Total expanded water to Accomodate)

 Minimum Tank Size  (Gallons)

Don’t know what size tank to choose? Always go bigger!