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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 is expressed as a percentage and indicates how much moisture the air is holding relative to the maximum it could hold at that temperature.
The calculator uses the relative humidity formula:
Where:
Explanation: This formula calculates the percentage of moisture in the air compared to the maximum amount the air can hold at that temperature.
Details: Accurate relative humidity measurement is crucial for weather forecasting, climate studies, industrial processes, agricultural planning, and maintaining comfortable indoor environments.
Tips: Enter vapor pressure and saturation vapor pressure values in hPa. Both values must be valid (greater than 0), and vapor pressure should not exceed saturation vapor pressure.
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 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 dryness, above 60% can promote mold growth.
Q3: How does temperature affect relative humidity?
A: Warmer air can hold more moisture, so relative humidity decreases as temperature increases if moisture content remains constant.
Q4: How is saturation vapor pressure determined?
A: Saturation vapor pressure depends primarily on temperature and can be calculated using various empirical formulas like the Magnus formula.
Q5: Why is relative humidity important in weather forecasting?
A: RH helps predict precipitation, fog formation, and is a key factor in calculating heat index and other comfort indices.