Calculators

Health

Calculator Use

This calculator will determine your maximum heart rate (MHR) and calculate your exercise target heart rate (THR) zones in beats per minute (bpm). Target heart rate (THR) zones can be calculated from your age, age and measured resting heart rate (RHR) or, measured maximum heart rate (MHR) and measured resting heart rate (RHR). These calculations are for adults older than 19 years old.

Max Heart Rate Equation

MHR = 220 - Age

Target Heart Rate Formula (Basic)

THR = MHR * %Intensity

Karvonen Formula

THR = [(MHR - RHR) x %Intensity] + RHR

Target Heart Rate Zone Calculation Methods

Basic by Age

This is historically the most common calculation and used by the American Heart Association. THR is calculated by multiplying percent intensity by the MHR.
Example: At 70% intensity THR = MHR x 0.70.

Karvonen by Age & RHR

This method calculates THR using the Karvonen Equation. MHR is calculated using age and allows you to enter a measured RHR.
Example: At 70% intensity THR = ((MHR - RHR) x 0.70) + RHR.

Karvonen by MHR & RHR

This method calculates THR using the Karvonen Equation and allows you to enter both a measured MHR and a measured RHR.
Example: At 50% intensity THR = ((MHR - RHR) x 0.50) + RHR. Where MHR - RHR is called your Heart Rate Reserve (HRR).

The American Heart Association recommends target heart rate zones for exercise at 50% to 85% intensity of MHR and defines a heart rate during moderately intense activities at 50-70% of MHR, and heart rate during hard physical activity at 70-90% of MHR.