Dew Point Calculator
Dew point is a more consistent "muggy vs dry" indicator than relative humidity alone — a dew point of 65°F (18°C) feels sticky whether the air temperature is 70°F or 95°F, while the same relative humidity percentage can feel completely different depending on temperature.
Free dew point calculator using the Magnus formula — enter temperature and relative humidity to see the dew point and a plain-language comfort level (dry to oppressive).
How it works
- Choose °F or °C
- Enter the air temperature and relative humidity
- See the dew point and a comfort-level label instantly
Frequently asked questions
Why use dew point instead of relative humidity?
Relative humidity depends on temperature — 50% RH can feel dry at 40°C or damp at 5°C. Dew point is more consistent: a dew point of 65°F (18°C) feels sticky whether the air is 70°F or 95°F, which makes it a better single number for how muggy it actually feels.
What formula does this use?
The Magnus formula, a standard meteorological approximation that's accurate to within about 0.4°C for typical atmospheric conditions.
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From the blog
Update history
- 2026-09-03 Bounded numeric fields are now sliders instead of number inputs.
- 2026-09-02 Launched: dew point calculator using the Magnus formula, with a comfort-level label from dry to oppressive. Entirely client-side.