Dew Point Calculator
Calculate the dew point temperature from air temperature and relative humidity.
What is Dew Point Calculator?
The dew point is the temperature at which air becomes saturated with moisture and water vapor condenses into liquid. It is a direct measure of absolute moisture content and a reliable indicator of how humid the air feels.
When the dew point is close to the air temperature, the air is nearly saturated and feels muggy; a large gap means the air is dry. The Magnus formula provides an accurate approximation from temperature and relative humidity.
How does the Dew Point Calculator work?
The letter a equals 17.27 and b equals 237.7, the standard Magnus coefficients for temperatures in degrees Celsius.
Relative humidity must be expressed as a fraction (RH/100) so the formula correctly weights the current saturation level.
How to use the Dew Point Calculator?
- Enter the current air temperature in degrees Celsius.
- Set the relative humidity percentage using the slider.
- Read the calculated dew point temperature.
- Check the comfort level to gauge how the air will feel.
Example
Try the calculator with your own numbers
- Enter your values in the input fields above.
- Adjust the values to match your situation.
- The result updates instantly as you change the inputs.
Benefits of using the Dew Point Calculator
- Understand true moisture content independent of air temperature.
- Anticipate condensation on surfaces and windows.
- Assess outdoor and indoor comfort more accurately than humidity alone.
Who should use the Dew Point Calculator?
- Students and professionals who need fast, accurate results.
- Anyone who wants to verify a manual calculation.
- People who prefer a quick answer over working it out by hand.
Tips for getting the most out of the Dew Point Calculator
- Double-check the values you enter before relying on the result.
- Use the calculator to verify manual calculations or estimates.
- Bookmark the page if you use it regularly.
Frequently Asked Questions
What is a comfortable dew point?
Generally, a dew point below 10°C feels dry, between 10 and 16°C is comfortable, 16 to 21°C feels slightly humid, and above 21°C feels oppressive or muggy.
Why does dew point matter more than relative humidity?
Relative humidity changes with temperature, but dew point is a fixed measure of actual moisture in the air. A high dew point means the air is truly humid regardless of the temperature.
Can the dew point exceed the air temperature?
No. The dew point can never be higher than the air temperature when relative humidity is at or below 100%, because the air cannot hold more moisture than its saturation limit at that temperature.
Skip the manual working — enter your numbers into the Dew Point Calculator and get a clean result instantly, right in your browser.
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