Who invented the 220 minus age formula?

The formula is most commonly attributed to Dr. William Haskell and Dr. Samuel Fox, who published it in 1970 as part of a review on exercise testing standards. However, Haskell himself later stated the formula was never derived from a specific study: it was a rough approximation based on observations from numerous data points compiled by Fox. It was never intended to be used as a definitive, universal standard for training zones.

How accurate is the 220 minus age formula?

The formula has a standard deviation of approximately ±10–12 bpm. This means about 68% of people have an actual MHR within 10–12 beats of the estimate, and about 32% fall outside that range, sometimes significantly so. A 45-year-old with an estimated MHR of 175 could realistically have a true MHR anywhere from 153 to 197 bpm. For training zone calculations, this level of imprecision is meaningful.

Does the 220 minus age formula work differently for women?

Yes. Research suggests the 220-minus-age formula tends to overestimate maximum heart rate in younger women and underestimate it in older women. A formula specifically derived for women (206 − 0.88 × age, from Gulati et al., 2010) has been proposed as more accurate for female populations. That said, individual variation within any gender group remains substantial, and the only definitive answer comes from direct measurement.

What is a better alternative to the 220 minus age formula?

The Tanaka formula (208 − 0.7 × age) and Gelish formula (207 − 0.7 × age) both outperform 220-minus-age in research, particularly for older adults. For training zone purposes, the Karvonen formula (which uses heart rate reserve rather than raw MHR percentage) produces more physiologically accurate zones regardless of which MHR estimate you use, because it also incorporates your resting heart rate.

What happens if my actual max heart rate is higher than 220 minus my age?

This is common and completely normal; roughly a third of people have true MHRs more than 12 bpm above their formula estimate. If you're regularly hitting heart rates higher than your formula-derived max without distress or symptoms, your actual MHR is simply higher than average for your age. Using a fitness wearable's peak HR reading from a hard race or intense workout as your personal MHR gives a better zone calculation than the formula would.

The 220 Minus Age Formula: How It Works and When It Falls Short

What Is the 220 Minus Age Formula?

The 220-minus-age formula estimates your maximum heart rate, the highest number of beats per minute your heart can reach during all-out physical effort. The formula is exactly what it sounds like:

Max Heart Rate = 220 − Age

A 30-year-old's estimated MHR is 190. A 50-year-old's is 170. A 65-year-old's is 155. It's on every treadmill display, gym chart, and fitness app. If you've ever been told to stay in a "zone" during exercise and seen a heart rate number next to it, this formula almost certainly produced that number.

The appeal is obvious: it requires no equipment, no testing, and no expertise. One subtraction and you have an anchor for every zone calculation on the planet.

Where the Formula Came From

The formula's origin is less rigorous than its ubiquity suggests. In 1970, Dr. William Haskell and Dr. Samuel Fox co-authored a review paper on exercise testing standards that included the formula. But as Haskell later explained in a 2001 interview, the number wasn't the result of a controlled study, it was a rough approximation assembled from data points across various sources, some of which weren't even studying maximum heart rate directly.

"It was never meant to be an absolute guide to rule people's training," Haskell said. The formula was a working approximation that got picked up, reproduced in textbooks, and eventually embedded in consumer fitness technology worldwide, far beyond what the original authors intended.

Subsequent research has produced better-fitting formulas. But the original stuck because it's simple, and simple gets repeated.

How Accurate Is 220 Minus Age?

Several large meta-analyses have measured the formula's accuracy against directly measured MHR values across diverse populations. The consistent finding: a standard deviation of approximately ±10–12 bpm.

Here's what that means practically for a 45-year-old (estimated MHR: 175 bpm):

Age 45: MHR Estimate vs. Likely Range

Formula estimate: 175 bpm
68% of people: 163–187 bpm (±12 bpm)
95% of people: 151–199 bpm (±24 bpm)

Your true MHR could be 24 bpm above or below the estimate

Scatter plot showing measured maximum heart rate versus age for a large population. The 220-minus-age formula line runs through the chart in red with a translucent ±12 bpm error band. Many individual data points fall outside the band, including one outlier annotated as Predicted 162, Actual 194 — Measured max heart rates scattered around the 220-minus-age line. The shaded band represents ±12 bpm, roughly one standard deviation. About 1 in 3 people fall outside it.

At the extremes, someone with a true MHR of 199 who's been calculating zones based on 175 has been training in zones that are 20+ bpm too low. Their "Zone 4 threshold" effort is Zone 2. This isn't academic, it explains why many people find heart rate zone training produces underwhelming results when using formula-derived targets without adjustment.

When the Formula Breaks Down Most

Older adults: The 220-minus-age formula consistently underestimates MHR in people over 50–55. Most newer formulas (Tanaka, Gelish) use a smaller age coefficient (0.7 rather than 1.0), which produces higher MHR estimates at older ages, estimates that better match measured values in this population.

Well-trained athletes: Many athletes have MHRs significantly higher than age-predicted values. This is partly genetic and partly the result of years of training that has maintained cardiac output capacity better than age-matched sedentary peers.

Women: Research by Gulati et al. (2010) found that the standard formula overestimates MHR in younger women and underestimates it in older women, and proposed a sex-specific formula (206 − 0.88 × age) as more accurate for female populations.

People on beta-blockers: These medications directly lower maximum heart rate. Formula-derived zones are meaningless for people on beta-blockers; perceived exertion or clinical guidance should guide training intensity instead.

Better Formulas for MHR Estimation

Two formulas consistently outperform 220-minus-age in research:

Formula	Equation	Basis
220 − Age	220 − age	Approximation, 1970
Tanaka (2001)	208 − (0.7 × age)	Meta-analysis, 18,712 subjects
Gelish (2007)	207 − (0.7 × age)	Treadmill testing, broad age range
Gulati (women)	206 − (0.88 × age)	Women-specific population study

Line chart comparing four max heart rate formulas from age 20 to 80. Four colored lines represent 220-minus-age in red, Tanaka in blue, Gelish in teal, and the Gulati women's formula in purple. The lines diverge visibly after age 50, with a vertical callout at age 70 highlighting the gap between 220-minus-age and the newer formulas — How the four major MHR formulas compare across the lifespan. The gap between 220-minus-age and the Tanaka or Gelish formulas widens significantly after age 50.

The Tanaka formula is the most rigorously derived and most commonly cited alternative. For a 50-year-old: 220-minus-age gives 170 bpm, while Tanaka gives 173 bpm, a small difference at younger ages that grows to 5–8 bpm difference by age 70. In absolute terms, these improved formulas narrow the error slightly but don't eliminate the fundamental problem of individual variation.

Why Karvonen Beats Any MHR Formula for Training Zones

Here's the key insight: even if you had a perfect MHR estimate, using raw percentages of that MHR to set zones ignores another major source of individual variation, your resting heart rate.

Consider two 40-year-olds with identical estimated MHRs of 180 bpm. One has a resting heart rate of 48 (trained cyclist), the other has 78 (sedentary office worker). Their cardiovascular fitness levels are completely different, but raw MHR percentage gives them identical zones: Zone 2 = 108–126 bpm for both.

The Karvonen formula fixes this by calculating zones from heart rate reserve, the gap between resting and maximum HR. For the trained cyclist (HRR = 132), Zone 2 using Karvonen is 127–140 bpm. For the sedentary person (HRR = 102), it's 109–119 bpm. That 20+ bpm difference reflects the real difference in their cardiovascular capacity.

Get Karvonen zones, not just MHR% Enter age and resting heart rate to get zones calibrated to your actual cardiovascular range.

When 220 Minus Age Is Good Enough

The formula earns criticism it deserves, but it has its place. For general health and wellness exercise (not serious training), staying somewhere in the moderate aerobic range is what matters, and 220-minus-age zones get you close enough. If you're walking for general fitness or doing casual gym workouts, the formula's imprecision is unlikely to undermine your goals.

It's also a useful starting point before you have better data. If you don't know your resting heart rate or haven't tested your MHR, 220-minus-age gets you into the right ballpark, and you can refine as you gather more information about your own physiology.

Where it breaks down is when people use it as a hard limit ("I shouldn't go above X bpm") or when they're training seriously for performance goals and zone accuracy matters. In those cases, measuring your resting heart rate and using the Karvonen formula, or better yet, directly testing your MHR, will produce meaningfully better training outcomes.

This article is for informational purposes only and does not constitute medical advice. Please consult a physician or certified fitness professional before performing maximal exercise tests or starting a new training program.