About the Dew Point Temperature Calculator

The Dew Point Calculator is a free online tool that computes the dew point temperature from air temperature and relative humidity. The dew point is the temperature at which air becomes saturated with water vapor, causing condensation. Understanding dew point is essential for meteorology, weather forecasting, HVAC design, and thermodynamics.


What You Can Calculate


Formula Used

The calculator uses the Magnus-Tetens approximation:

Td = (243.12 × α) / (17.62 − α)

where α = ln(RH/100) + (17.62 × T) / (243.12 + T), with T = air temperature in °C and RH = relative humidity (%).


How to Use the Calculator

  1. Enter the air temperature and select the unit (°C or K).
  2. Enter the relative humidity in percent (%).
  3. The calculator automatically computes the dew point temperature in the selected unit.
  4. Adjust the inputs to analyze different environmental or HVAC conditions.

Applications of Dew Point Analysis