Heat index

Calculate Heat index instantly with the exact formula and a worked example. Free online calculator — no signup.

Temp, °F

Humidity, %

Heat index

99.6777°F

Rothfusz (NWS)Calculate Heat index instantly with the exact formula and a worked example. Free online calculator — no signup.

HI °F

99,7

HI °C

37,6

A physics calculator based on a standard formula. Enter the parameters to compute the result instantly — for coursework, labs, and engineering tasks.

The calculator computes Heat index (°F) from parameters:

Example 1

Temp, °F = 90, Humidity, % = 60

→ Heat index: 99.68 °F

Example 2 (×1.5)

Temp, °F = 135, Humidity, % = 90

→ Heat index: 501.95 °F

More about: Heat index

The “Heat index” calculator computes Heat index in °F from 2 parameters: temp, °f, humidity, %.

A standard physics formula used in educational and engineering tasks.

With parameters Temp, °F = 90, Humidity, % = 60 the result is 99.68 °F (Rothfusz (NWS)).