Enter the body temperature into the calculator to determine the heart rate. This calculator can also evaluate any of the variables given the others are known.

Glaister Equation Formula

The following formula is used to calculate the Glaister Equation.

HR = 98.4 + 0.41 * (T - 36.9)


  • HR is the heart rate (beats per minute) T is the body temperature (°C)

To calculate the heart rate using the Glaister Equation, subtract 36.9 from the body temperature. Multiply the result by 0.41, then add 98.4 to the product.

How to Calculate Glaister Equation?

The following steps outline how to calculate the Glaister Equation:

  1. First, determine the value of T, which represents the body temperature in °C.
  2. Next, subtract 36.9 from the value of T.
  3. Multiply the result from step 2 by 0.41.
  4. Add 98.4 to the result from step 3.
  5. Finally, calculate the heart rate (HR) using the Glaister Equation.
  6. After inserting the value of T and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge:

body temperature (T) = 37.5 °C