max working heart rate for age
This maximum rate is based on the person's age. An estimate of a person's maximum age-related heart rate can be obtained by subtracting the person's age from 220. For example, for a 50-year-old person, the estimated maximum age-related heart rate would be calculated as 220 - 50 years = 170 beats per minute (bpm).
One simple method to calculate your predicted maximum heart rate, uses this formula: 220 - your age = predicted maximum heart rate. Example: a 40-year-old's predicted maximum heart rate is 180 beats/minute. There are other formulas that take into account the variations in maximal heart rate with age and gender.