How it works
Calculate the dew point temperature from current air temperature and relative humidity.
Input query strings and outputs
Use an input name in this page’s URL as ?name=value, and join additional inputs with &. Portable shared links may instead use the compact ?ac= state parameter.
Input query strings
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?temp=Temperature (°C)Number · Optional · Default: 25
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?humidity=Relative Humidity (%)Number · Optional · Default: 50
Outputs
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resultResultText · Primary output
result contains the calculator’s complete rendered result area, including its visible result cards, tables, charts, and messages.
Calculate the temperature at which air becomes saturated
Description
The Dew Point Calculator is a meteorological tool used to find the “Dew Point”—the specific temperature to which air must be cooled to become saturated with water vapor. When the air temperature reaches the dew point, water begins to condense, forming dew, frost, or fog. This tool is vital for meteorologists, pilots, and HVAC technicians to assess comfort levels and the risk of condensation.
Inputs
- Temperature (°C): The current ambient air temperature in Celsius.
- Relative Humidity (%): The percentage of moisture currently in the air.
Outputs
- Dew Point: The temperature (°C) at which condensation will begin to form.
Chart
- N/A: This tool provides a direct numeric atmospheric result.
“Good to Know”
- Magnus Formula: This calculator uses the Magnus-Tetens approximation, a widely accepted formula for calculating dew point from temperature and humidity.
- Comfort Levels:
- < 10°C: Very dry and comfortable.
- 15°C - 20°C: Getting humid; “sticky” feeling.
- > 21°C: Oppressive and extremely humid.
- The Gap: The larger the difference between the air temperature and the dew point, the “drier” the air feels.
Examples
Example 1: Typical Summer Day
- Input: Temp: 30°C, Humidity: 60%
- Output: 21.4 °C (Oppressive)
Example 2: Dry Winter Day
- Input: Temp: 10°C, Humidity: 30%
- Output: -6.0 °C
Example 3: Mild Spring Day
- Input: Temp: 20°C, Humidity: 50%
- Output: 9.3 °C (Comfortable)