Dew point calculator

The temperature at which air becomes saturated — from air temperature and relative humidity, via the Magnus formula.

Magnus-formula estimate (α=17.27, β=237.7 °C). Valid roughly −40 to 60 °C — an estimate, not a measurement.

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How to use

  1. Enter the air temperature (°C or °F).
  2. Enter the relative humidity.
  3. Read the dew point and comfort band.

What it supports

Magnus approximation: −40…60 °C, RH 1–100 %. Dew point ≤ air temperature by construction. Above ~60 % RH the error vs. a sling psychrometer stays under ~0.4 °C; it grows in very dry, very hot air.

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