Measuring Your Maximum Heart Rate (HR_max)

Your maximum heart rate is an important piece of information. In order to train correctly, getting enough stimulation to provide a benefit without working so hard as to burn off excessive muscle, you need to work within a certain percentage range of your maximum heart rate.

The calculator below asks for your weight and age. It displays your HR_max according to several methodologies, as well as the training zones associated with each HR_max.

Most automated aerobic equipment (like treadmills, elliptical striders, stair climbers and exercise bikes) will use the common Fox & Haskell formula shown below. But there are other ways of calculating your maximum heart rate, and therefore your training zone.

This page lists several, with associated formulae.

The most accurate way of measuring HR_max for an individual is via a cardiac stress test. In such a test, the subject exercises while being monitored by an electrocardiogram (ECG). During the test, the intensity of exercise is periodically increased (if a treadmill is being used, through increase in speed or slope of the treadmill) until the subject can no longer continue, or until certain changes in heart function are detected in the ECG (at which point the subject is directed to stop). Typical durations of such a test range from 10 to 20 minutes.

Since the HR_max declines with age, this test does not hold permanent value.

Conducting an accurate maximal exercise test requires expensive equipment, and should only be performed in the presence of medical staff due to risks associated with high heart rates. Instead, people typically use predictive formulae to estimate their individual Maximum Heart Rate. The most common formula encountered is:

HR_max = 220 − age (can vary)

This is attributed to various sources, often "Fox & Haskell". While the most common (and easy to remember and calculate), this particular formula is not considered by some to be a good predictor of HR_max.

1. A 2003 study [1] of 43 different formulae for HR_max (including the one above) concluded the following:
2. No "acceptable" formula currently existed, (they used the term "acceptable" to mean acceptable for both prediction of VO_2max, and prescription of exercise training HR ranges)

The most accurate formula of those examined was:

HR_max = 205.8 − (0.685 * age)

This was found to have a standard of error that, although large (6.4 bpm), was still deemed to be acceptable for the use of prescribing exercise training HR ranges.

Other often cited formulae are:

HR_max = 206.3 − (0.711 * age)

(Often attributed to "Londeree & Moeschberger from the University of Missouri–Columbia")

HR_max = 217 − (0.85 * age)

(Often attributed to "Miller et al. from Indiana University")

Sally Edwards, CEO of Heart Zones proposes a set of gender specific formula for predicting Maximum Heart Rate.^[5]

For males: 210 - 1/2 your age - 5% of total body weight (in pounds) + 4 = HR_max

For females: 210 - 1/2 your age - 5% of total body weight (in pounds) + 0 = HR_max