Heat Index Calculator
Calculate the heat index (feels-like temperature) from air temperature and humidity using the Steadman formula. See danger level classification.
How to Use the Heat Index Calculator
- Enter the known physical values in the corresponding fields.
- Select the appropriate units if multiple options are available.
- The unknown value is computed instantly from the formula.
- Review the result and the formula explanation below.
Referência Rápida
| De | Para |
|---|---|
| Speed of light | 299,792,458 m/s |
| Gravity (g) | 9.807 m/s² |
| Avogadro's number | 6.022 × 10²³ |
| Boltzmann const. | 1.38 × 10⁻²³ J/K |
| Elementary charge | 1.602 × 10⁻¹⁹ C |
| Planck's const. | 6.626 × 10⁻³⁴ J·s |
Casos de Uso
- •Solving physics homework or exam problems with the correct formula.
- •Verifying experimental measurements and calculations in the lab.
- •Understanding physical relationships between quantities.
- •Quick engineering calculations for design or estimation.
Fórmula
HI = -8.785 + 1.611T + 2.339RH - 0.146T×RH - 0.013T² - 0.016RH² + 0.002T²×RH + 0.001T×RH² - 0.000004T²×RH².
Perguntas Frequentes
How to use?
Enter the data and click the calculate button.
What is heat index?
The heat index combines air temperature and relative humidity to determine the human-perceived equivalent temperature — how hot it actually feels.
When is the heat index dangerous?
A heat index above 32°C (90°F) is considered dangerous. Above 41°C (106°F) is extremely dangerous with risk of heat stroke.
Is it free?
Yes, all calculators are completely free.