Calculate the dew point temperature from air temperature and relative humidity.
Enter temperature and relative humidity, then click Calculate.
The dew point is the temperature at which air becomes saturated with water vapor and condensation begins. It is a direct measure of atmospheric moisture content, independent of temperature. The theoretical calculation uses the Magnus formula: e_s(T) = 6.112 × exp((17.67 × T) / (T + 243.5)), where e_s is the saturation vapor pressure at temperature T. The actual vapor pressure e = (RH/100) × e_s(T). The dew point Td is then found by solving e = e_s(Td), giving Td = (243.5 × ln(e/6.112)) / (17.67 - ln(e/6.112)). A higher dew point means more moisture in the air. Dew point above 20°C feels humid and uncomfortable, below 10°C feels dry and pleasant. This calculator is essential for meteorology, HVAC design, agriculture, and building science.
- Enter the Air Temperature in degrees Celsius.
- Enter the Relative Humidity as a percentage (0-100%).
- Click Calculate Dew Point to compute the dew point.
- The result shows vapor pressures and the dew point temperature.
- An interpretation of the dew point level is provided.
- Click Reset to restore default example values.