Why must RH be above zero?

At RH = 0 the vapor pressure is zero and dew point is undefined for this model.

Is this valid below freezing?

The curve is treated as liquid water; frost point and ice effects are not modeled.

Dew Point Calculator

Computes water vapor partial pressure from dry-bulb temperature and RH, then inverts the same vapor-pressure curve to obtain dew point. Intended for quick HVAC and classroom checks, not meteorological certification.

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So geht's

1Enter dry-bulb temperature in °C.
2Enter relative humidity strictly between 0 and 100%.
3Read saturation pressure, vapor pressure, and dew point.

Häufige Fragen

Why must RH be above zero?: At RH = 0 the vapor pressure is zero and dew point is undefined for this model.
Is this valid below freezing?: The curve is treated as liquid water; frost point and ice effects are not modeled.