Dew Point Calculator

Use it when your task matches one of these common needs: Estimate dew point from weather readings. Compare humidity comfort more clearly than relative humidity alone. It works best when you already know the measurements, amounts, units, or options the page asks for.

In plain language: The calculator converts Fahrenheit to Celsius, uses the Magnus approximation with relative humidity, then converts the dew point back to Fahrenheit. The examples on the page are there so you can compare your inputs with a worked example before copying the answer.

Temperature F: the current air temperature in degrees Fahrenheit. Relative humidity %: how close the air is to saturation at that temperature. Dew point: the temperature where the air would be saturated and water vapor could start condensing.

Read the headline answer, then check the smaller lines beside it. For everyday tools, those lines usually show the distance, time, cost, units, or setting that made the answer change.

This is an approximation from temperature and relative humidity. Instrument readings and official forecasts can differ. Also check the unit, scale, mode, and result limit because small input changes can change the answer.

Relative humidity changes when temperature changes. Dew point gives a more direct clue about how much moisture is actually in the air, so a higher dew point usually feels more humid.

No. The calculator runs in your browser tab. Your recent answers stay only on the page while you use it, and they are not sent to a server.