Superheat & Subcooling Calculator
Quick refrigerant charge check
Why this tool matters
Solve the calculation or lookup now, then use the demo to see how the answer can stay visible on the morning operating board.
Next best step
Use the result in the field, then see the interactive demo when you want the answer to stay visible after this visit.
Superheat Targets
Fixed Orifice: 8-12°F
TXV System: 5-10°F
Low (<5°F): Overcharge or TXV flooding
High (>15°F): Undercharge or restriction
Subcooling Targets
Target Range: 10-15°F
Most Systems: 12°F ideal
Low (<8°F): Undercharge
High (>18°F): Overcharge or restriction
Quick Guide
Superheat = Suction Line Temp - Saturation Temp (from suction pressure)
Subcooling = Saturation Temp (from liquid pressure) - Liquid Line Temp
Pro Tip: Always check both superheat AND subcooling for accurate diagnosis
Automatic Refrigerant Charge Logs
AssureStep AssureStep gives you unlimited equipment tracking, revenue opportunity scanning, tracks charge history, and flags systems trending toward failure.