Humidity Calculator
From °F Temperature & Dew Point
°F
°F
From °C Temperature & Dew Point
°C
°C
Formula
RH = 100 × exp((17.625 × Td)/(243.04 + Td)) / exp((17.625 × T)/(243.04 + T))
Frequently Asked Questions
What is relative humidity?
Relative humidity is the ratio of the current amount of water vapor in the air to the maximum amount the air can hold at that temperature, expressed as a percentage. 100% means the air is fully saturated.
What is a comfortable humidity level?
Indoor relative humidity of 30–50% is generally comfortable. Outdoors, comfort depends more on dew point: below 55°F (13°C) is comfortable, 60–65°F (15–18°C) is noticeable, and above 70°F (21°C) is oppressive.
What is the difference between dew point and humidity?
Dew point is the temperature at which air becomes saturated and dew forms. It's an absolute measure of moisture. Relative humidity changes with temperature — the same moisture content gives different RH% at different temperatures.
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