Dew Point Calculator
Calculate dew point, relative humidity, or temperature using the Magnus formula. Supports °C, °F, and K with comfort-level assessment.
Calculate
Choose a calculation type, enter your values, and click Calculate Now to see dew point results with comfort levels and step-by-step solutions.
Result
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Step-by-Step Solution
Complete User Guide
What is Dew Point?
The dew point is the temperature at which air becomes saturated with water vapor and condensation starts to form. It is always less than or equal to the air temperature. Dew point is a better indicator of comfort than relative humidity alone, because it directly measures the amount of moisture in the air. This calculator uses the Magnus formula, widely used in meteorology and HVAC applications.
Magnus Formula
α = (A × T) / (B + T) + ln(RH / 100)
Td = (B × α) / (A − α)
Where A = 17.27, B = 237.7 °C, T = temperature (°C), RH = relative humidity (%), Td = dew point (°C)
4 Calculation Types
Dew Point
Enter air temperature and relative humidity. Get dew point with comfort level.
Relative Humidity
Enter air temperature and dew point. Get relative humidity (%).
Temperature
Enter dew point and relative humidity. Get the air temperature.
Convert Units
Convert between °C, °F, and K.
Dew Point Comfort Levels
| Dew Point (°C) | Comfort Level | Description |
|---|---|---|
| < 10 | Dry | Very comfortable, dry air. |
| 10 – 16 | Comfortable | Pleasant conditions. |
| 16 – 18 | Slightly Humid | Most people comfortable. |
| 18 – 21 | Humid | Some discomfort, sticky feeling. |
| 21 – 24 | Very Humid | Uncomfortable, oppressive. |
| > 24 | Extremely Humid | Dangerous, heat exhaustion risk. |
Important Notes
- Dew point is always ≤ air temperature.
- Magnus formula is accurate for −45 °C to 60 °C.
- Relative humidity must be between 0 % and 100 %.
- Dew point is a better comfort indicator than RH alone.