Dew Point Calculator

Fahrenheit      Celsius

Temperature T (°)     


Dewpoint Td (°)     


Relative Humidity RH (%)     



  


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About Dew Point Calculator

This Dew Point Calculator helps you estimate the temperature at which moisture in the air begins to condense — known as the dew point. It's an essential tool for HVAC engineers, weather forecasters, and anyone monitoring air moisture and comfort levels.

How to Use the Dew Point Calculator

Simply enter:

  • Air Temperature (in °C or °F)
  • Relative Humidity (%)

The calculator will return the dew point temperature — the point at which air becomes saturated and water vapor begins to condense.

Dew Point Formula (Magnus Approximation)

Dew Point = (b × α(T, RH)) / (a − α(T, RH))
where:
α(T, RH) = ln(RH/100) + (a × T) / (b + T)
a = 17.27, b = 237.7°C

This approximation is accurate for temperatures between 0°C and 60°C.

Common Use Cases

  • HVAC system monitoring and control
  • Predicting condensation in buildings or pipelines
  • Weather prediction and climate study
  • Industrial drying and storage processes
  • Greenhouse and agriculture management

Why Use a Dew Point Calculator?

Monitoring dew point helps maintain comfort indoors, prevent mold or corrosion, and ensure proper humidity control in sensitive environments. It’s crucial for climate regulation, refrigeration, and air quality assurance.

Frequently Asked Questions (FAQs)

What is dew point?

The dew point is the temperature at which air becomes fully saturated with water vapor, leading to condensation.

What’s the ideal indoor dew point?

Ideal indoor dew points range between 10°C to 16°C (50°F to 60°F) for comfort and mold prevention.

How is dew point different from humidity?

Humidity is relative, while dew point is absolute — it shows the actual temperature at which condensation occurs.

Can dew point be higher than temperature?

No. Dew point is always less than or equal to the current air temperature.

Why does low dew point feel dry?

Low dew points mean less moisture in the air, which can dry out skin, eyes, and respiratory passages.