Enter the air temperature and relative humidity into the calculator to determine the discomfort index.

Discomfort Index Formula

The following equation is used to calculate the Discomfort Index.

DI = T - .55 * (1-.01*RH) * (T-14.5)
  • Where Di is the discomfort index
  • T is the air temperature (C)
  • RH is the relative humidity

What is a Discomfort Index?


A discomfort index measures how much discomfort a person feels with a given air temperature and relative humidity. The higher the relative humidity and the air temperature, the greater the discomfort index. Conversely, the lower the temperature and humidity the lower the discomfot.

How to Calculate Discomfort Index?

Example Problem:

The following example outlines the steps and information needed to calculate Discomfort Index.

First, determine the air temperature. In this example, the air temperature is measured to be 40C.

Next, determine the relative humidity. In this case, the relative humidity is calculated to be 40%.

Finally, calculate the discomfort index using the formula above:

DI = T – .55 * (1-.01*RH) * (T-14.5)

DI = 40 – .55 * (1-.01*40) * (40-14.5)

DI = 31.585