OhMyCalc

Dew Point Calculator

Calculate the dew point temperature from air temperature and relative humidity using the Magnus formula. See comfort level and temperature spread.

How to Use the Dew Point Calculator

  1. Enter the known physical values in the corresponding fields.
  2. Select the appropriate units if multiple options are available.
  3. The unknown value is computed instantly from the formula.
  4. Review the result and the formula explanation below.

快速参考

Speed of light299,792,458 m/s
Gravity (g)9.807 m/s²
Avogadro's number6.022 × 10²³
Boltzmann const.1.38 × 10⁻²³ J/K
Elementary charge1.602 × 10⁻¹⁹ C
Planck's const.6.626 × 10⁻³⁴ J·s

使用场景

公式

γ = ln(RH/100) + (17.67 × T) / (243.5 + T). Dew Point = 243.5 × γ / (17.67 - γ).

常见问题

How to use?
Enter the data and click the calculate button.
What is the dew point?
The dew point is the temperature at which air becomes saturated and water vapor begins to condense into liquid water.
What does the spread mean?
The spread is the difference between the current temperature and the dew point. A smaller spread means the air is closer to saturation.
Is it free?
Yes, all calculators are completely free.