Dew Point Calculator
Calculate the dew point temperature based on ambient temperature and relative humidity. Essential for weather analysis, HVAC, and comfort assessment.
Published by:
isCalculator Editorial Team
Was this calculator helpful?
How to use this tool?
Follow these steps to calculate the dew point using the Magnus approximation:
- Enter Temperature (°C) – Input the air temperature in degrees Celsius (e.g., 25). The calculator accepts values from -100 to 100 °C.
- Enter Relative Humidity (%) – Input the relative humidity as a percentage between 0 and 100 (e.g., 60).
- Click "Calculate" – Press the button to compute the dew point.
- Read the Result – The dew point appears in °C, displayed in a green alert box. The formula used is shown below the result for reference.
Note: If you enter invalid numbers or out-of-range values, an error message will guide you to correct the input.
Previous Results
| Result | Inputs | Date |
|---|
Frequently Asked Questions
Dew point is the temperature at which air becomes saturated with moisture and water vapor condenses into liquid water. It is a measure of atmospheric humidity.
The calculator uses the Magnus formula: Td = (b * α) / (a - α), where α = (a*T)/(b+T) + ln(RH/100), a=17.27, b=237.7°C.
Dew point indicates comfort levels, fog formation, and frost risk. High dew points feel muggy, while low dew points feel dry.