Dew Point Calculator - Calculator See


Dew Point Calculator

Calculate atmospheric dew point from ambient air temperature and relative humidity using the Magnus-Tetens formula.

Calculator Inputs

°F
Dry bulb thermometer reading.
%
Atmospheric moisture percentage.

Calculated Results

Atmospheric Dew Point
62.2°F (16.8°C)
Comfort Sensation Noticeably Humid / Muggy
Dew Point in Celsius 16.8°C
Condensation Threshold Water condenses below 62.2°F
Values calculate live as you adjust inputs.

About Dew Point Calculator

Computes the dew point temperature at which air must be cooled at constant pressure to achieve 100% relative humidity and produce condensation.

What is Dew Point Calculator?

Computes the dew point temperature at which air must be cooled at constant pressure to achieve 100% relative humidity and produce condensation.

How to Use This Calculator

  1. Enter temperature in °F.
  2. Select relative humidity percentage.
  3. Review dew point and comfort level.

The Mathematical Formula & Variables

Dew Point (°C) = (b * alpha) / (a - alpha), where alpha = (a*T)/(b+T) + ln(RH/100)

Step-by-Step Worked Example

Scenario: 78°F ambient temperature with 60% relative humidity.

  1. Calculates dew point = 62.2°F (16.8°C).
  2. Dew points above 60°F feel noticeably muggy; above 70°F feels oppressive.

Result: Dew Point: 62.2°F

Frequently Asked Questions

Why is dew point a better measure of comfort than relative humidity?

Dew point reflects absolute water vapor content in the air, while relative humidity changes with temperature.