Formula & example
Superheat=Tline−Tsat.
A 52°F suction line with 40°F saturation temperature has 12°F superheat.
HVAC engineering calculator · Updated Sep 17, 2026
HVAC Superheat Calculator — Suction vs Saturation Temperature
Calculate evaporator superheat from measured suction-line temperature and evaporating saturation temperature in °F or °C.
Inputs
Result
Superheat 12°
Positive superheat: vapor is above the entered saturation temperature
Assumptions & limits
- Saturation temperature must come from the correct refrigerant pressure-temperature data.
- This temperature-difference calculator does not infer refrigerant saturation from pressure.
Frequently asked questions
What does this HVAC Superheat Calculator calculate?
Calculate evaporator superheat from measured suction-line temperature and evaporating saturation temperature in °F or °C.
Can I use SI and US customary units?
Yes. The calculator exposes the unit basis in the inputs and reports useful cross-unit outputs where the engineering workflow benefits from them.
Is this a replacement for HVAC design software?
No. It is a transparent deterministic engineering calculator for sizing, diagnostics and cross-checks. Final equipment, duct and refrigeration decisions should use measured conditions, manufacturer data and applicable codes or standards.