Relative Humidity Calculator
Calculate relative humidity based on actual and saturation water vapor pressures
Calculator
Enter two known values to calculate the missing parameter. You can use temperature, dew point, or actual vapor pressure, and select units as needed.
About the Relative Humidity Calculator
The Relative Humidity Calculator is a user-friendly online tool for calculating relative humidity (RH) based on temperature, dew point, and actual water vapor pressure. Relative humidity is the ratio of the actual water vapor in the air to the maximum possible at a given temperature, expressed as a percentage. This property is essential in meteorology, climate studies, HVAC engineering, and environmental science.
What You Can Calculate
- Relative Humidity (RH %): Measure the moisture content of air relative to saturation.
- Actual Vapor Pressure (e): Determine the partial pressure of water vapor in the air.
- Dew Point (Td): Calculate the temperature at which air becomes saturated and condensation begins.
Formula Used in the Calculator
The calculator uses standard thermodynamic relationships:
- RH (%) = (Actual Vapor Pressure / Saturation Vapor Pressure) × 100
- Saturation vapor pressure is calculated using temperature-dependent empirical formulas.
How to Use the Relative Humidity Calculator
- Enter two known variables among temperature (T), dew point (Td), actual vapor pressure (e), or relative humidity (RH).
- Leave the unknown variable blank; the calculator will solve for it automatically.
- Select the appropriate units for temperature (°C or K) and vapor pressure (hPa, Pa, or kPa).
- The result is displayed instantly, providing precise values for scientific, engineering, or meteorological applications.
Applications of Relative Humidity Measurement
- Weather Forecasting: Determine moisture content in the atmosphere for accurate predictions.
- HVAC Design: Optimize air conditioning, heating, and ventilation systems for indoor comfort.
- Environmental Monitoring: Assess humidity for agricultural, industrial, and research purposes.
- Thermodynamics & Laboratory Use: Calculate vapor pressure and dew point for scientific experiments.
Using this Relative Humidity Calculator, students, scientists, engineers, and meteorologists can quickly determine humidity-related properties, making it easier to analyze air moisture content and support both educational and industrial applications.