Subcooling Calculator

Find system subcooling from your measured liquid saturation temperature and liquid line temperature.

Liquid saturation temp (°F, from P–T chart)

Liquid line temperature (°F)

Subcooling

—

How it works: Subcooling = liquid saturation temperature − liquid line temperature. Read the saturation temperature off your gauge’s P–T scale for your refrigerant and measured liquid (high-side) pressure. Most TXV/EEV systems target roughly 8–12°F of subcooling, but always charge to the manufacturer’s spec on the nameplate. Low subcooling usually means an undercharge; high subcooling points to an overcharge or a liquid-line restriction.