Relative Humidity Calculator
Free relative humidity calculator using the Magnus formula. Calculate humidity percentage from dry bulb temperature and dew point or wet bulb temperature.
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Calculate Relative Humidity
Relative humidity indicates how much moisture is in the air compared to the maximum it can hold at that temperature. Our calculator uses the Magnus formula to accurately compute relative humidity from either the dew point or wet bulb temperature.
What Is Relative Humidity?
Relative humidity (RH) is the ratio of the current amount of water vapor in the air to the maximum amount possible at that temperature, expressed as a percentage. At 100% RH, the air is saturated and fog or dew forms. RH affects comfort, health, and many industrial processes.
Relative Humidity Formula
RH = (e / es) × 100%, where e = actual vapor pressure, es = saturation vapor pressureWhy Calculate Relative Humidity?
Indoor Comfort
Maintain optimal 30-50% humidity for health and comfort indoors.
Weather Understanding
Predict fog, dew, and precipitation likelihood from humidity levels.
Industrial Applications
Control humidity for manufacturing, storage, and agriculture.
How to Use This Calculator
Common Applications
HVAC Systems
Monitor and control indoor humidity for building comfort and health.
Meteorology
Weather stations calculate humidity for forecasting precipitation.
Agriculture
Greenhouses and storage facilities monitor humidity for optimal conditions.
Museums & Archives
Preserve artifacts and documents by maintaining proper humidity levels.
Frequently Asked Questions
For most people, 30-50% relative humidity is ideal indoors. Below 30% can cause dry skin and respiratory issues. Above 60% feels sticky and promotes mold growth.