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Relative Humidity Formula:
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Relative humidity (RH) is the ratio of the partial pressure of water vapor to the equilibrium vapor pressure of water at a given temperature. It represents the amount of moisture in the air relative to the maximum amount the air can hold at that temperature.
The calculator uses the relative humidity formula:
Where:
Explanation: The formula calculates the percentage of moisture in the air compared to the maximum amount the air can hold at that temperature.
Details: Relative humidity is crucial for weather forecasting, climate studies, industrial processes, agricultural planning, and maintaining comfortable indoor environments. It affects human comfort, health, and various industrial and biological processes.
Tips: Enter actual vapor pressure and saturation vapor pressure in hPa. Both values must be positive numbers.
Q1: What is the difference between absolute and relative humidity?
A: Absolute humidity measures the actual amount of water vapor in the air (g/m³), while relative humidity expresses this amount as a percentage of the maximum possible at that temperature.
Q2: What are typical relative humidity ranges?
A: Comfortable indoor RH is typically 30-50%. Below 30% can cause dry skin and respiratory issues, while above 60% can promote mold growth and feel uncomfortable.
Q3: How does temperature affect relative humidity?
A: Warmer air can hold more moisture, so relative humidity decreases as temperature increases if the actual moisture content remains constant.
Q4: Why is relative humidity important in weather forecasting?
A: RH helps predict precipitation, fog formation, and is a key factor in heat index calculations that determine how hot it feels to humans.
Q5: How is relative humidity measured in practice?
A: Instruments called hygrometers measure relative humidity directly, often using materials that change properties (like hair length or electrical capacitance) with humidity changes.