What is the Humidity Calculator?
Convert between humidity measures with this free humidity calculator. Enter dry-bulb temperature plus relative humidity, dew point, or wet-bulb temperature to get a full psychrometric summary — RH, dew point, wet-bulb, vapor pressure, absolute humidity (g/m³), specific humidity, and mixing ratio (g/kg). Uses Magnus-Tetens, Stull wet-bulb, and standard psychrometric relations at sea-level pressure. Metric and imperial units; results update instantly in your browser with no signup.
How to use the Humidity Calculator
- Choose what you know: relative humidity (%), dew point, or wet-bulb temperature.
- Select metric (°C) or imperial (°F) and enter dry-bulb temperature.
- Enter the second value for your chosen mode.
- Review all humidity metrics, comfort level, and calculation steps.
- Try presets such as 25°C at 60% RH or dry/wet bulb 30°C / 24°C.
Common use cases
- Converting between RH, dew point, and wet-bulb for weather or HVAC homework
- Computing mixing ratio and absolute humidity from a psychrometer reading
- Checking comfort and moisture content for greenhouse or storage conditions
- Understanding how dry-bulb and wet-bulb depression relate to humidity
- Pairing with the heat index and dew point calculators for complete weather analysis
Frequently asked questions
- What is the difference between relative and absolute humidity?
- Relative humidity (%) is water vapor as a fraction of saturation at the current temperature — it changes when temperature changes even if moisture content stays the same. Absolute humidity (g/m³) is the actual mass of vapor per volume of air.
- What is wet-bulb temperature?
- Wet-bulb temperature is read with a thermometer wrapped in a wet cloth. Evaporation cools the bulb until equilibrium; the difference between dry-bulb and wet-bulb indicates humidity. This calculator derives RH from dry and wet bulb via the psychrometric equation.
- What is mixing ratio?
- Mixing ratio is grams of water vapor per kilogram of dry air (g/kg). Unlike relative humidity, it does not change with temperature alone. It is widely used in meteorology and HVAC psychrometrics.
- What pressure is assumed?
- Mixing ratio and psychrometric calculations use standard sea-level pressure of 1013.25 hPa. Results at high altitude will differ slightly.
- How is this different from the dew point calculator?
- The dew point calculator focuses on dew point and condensation. This humidity calculator returns the full set of moisture variables including wet-bulb, mixing ratio, and specific humidity from three input methods.
