Home
Back
Relative Humidity Formula:
| From: | To: |
Relative Humidity (RH) is a measure of how much water vapor is in the air compared to the maximum amount the air could hold at that temperature. It's expressed as a percentage, with 100% meaning the air is fully saturated with water vapor.
The calculator uses the Relative Humidity formula:
Where:
Explanation: The equation compares the actual amount of water vapor in the air to the maximum possible amount at that temperature, giving a percentage that represents relative humidity.
Details: Relative humidity affects human comfort, health, building construction, and many industrial processes. It's crucial for weather forecasting, HVAC system design, and preventing mold growth.
Tips: Enter both vapor pressure values in kPa (kilopascals). Actual vapor pressure should be less than or equal to saturation vapor pressure for meaningful results.
Q1: What's the difference between absolute and relative humidity?
A: Absolute humidity measures the actual water vapor content (g/m³), while relative humidity measures how close the air is to saturation.
Q2: What is a comfortable relative humidity range?
A: For human comfort, 30-50% is generally recommended. Below 30% can cause dryness, above 60% promotes mold growth.
Q3: How does temperature affect relative humidity?
A: Warmer air can hold more water vapor, so relative humidity decreases as temperature rises (if water content stays the same).
Q4: How can I measure vapor pressure?
A: Vapor pressure can be calculated from dew point temperature or measured directly with specialized instruments.
Q5: Why does relative humidity matter in weather?
A: High RH can indicate potential for precipitation, fog, or discomfort, while low RH can increase fire danger.