Science

Heat Index Calculator

Perceived temperature from heat and humidity using the Rothfusz regression.

Inputs

Air temperature (°C)

Relative humidity (%)

Result

Heat index

40.4 °C

How it's calculated

Rothfusz regression HI(°F) from T(°F) and RH(%), with low/high adjustments

Why does humidity make heat feel worse?

Sweat cools you only when it evaporates. High humidity slows evaporation, so your body can't shed heat efficiently and core temperature rises.

Does heat index apply in the shade?

The NWS heat index assumes shady, light-wind conditions. Direct sun can add up to about 8 °C (15 °F) to the felt temperature.

Science

Wind Chill Calculator

Perceived temperature from air temperature and wind speed using the North American formula.

Science

Dew Point Calculator

Dew point temperature from air temperature and relative humidity (Magnus formula).

Science

Density Calculator

Solve for density, mass, or volume from the other two using ρ = m / V.

Science

Force Calculator

Newton's second law solver — find force, mass, or acceleration from the other two.