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How To Calculate Max Heart Rate: 8 Ways To Measure It

Plus, why is it important to know your true max?

One of the best ways to gauge your workout intensity is to monitor your heart rate. 

Because your heart rate is correlated with the intensity level of any type of physical activity, and the association is fairly linear, your heart rate during exercise can be an effective and practical way to quantify your effort level and estimate the number of calories you burn.

For this reason, heart rate training for runners has long been one of the most scientific approaches to endurance training and is relatively easy to carry out once you have a heart rate monitor and have defined your heart rate zones.

However, determining your heart rate zones can be as simple or complicated as you’d like it to be; the difference lies in how accurate you want them to be.

The more precise you are about calculating max heart rate, the more accurate your heart rate training will be.

But you need to know how to calculate max heart rate. Are maximum heart rate estimations adequate, or should you actually measure your maximum heart rate with a test?

In this guide, we will discuss how to calculate max heart rate and why it might be worth measuring your maximum heart rate rather than relying on an estimated maximum heart rate equation.

The word MAX.

What Is Maximum Heart Rate?

Your maximum heart rate (MHR or max HR) refers to your highest potential pulse, or the maximum number of times your heart can beat in a minute.

The faster your heart can beat, the higher your maximum heart rate.

What Factors Affect Max Heart Rate?

Interestingly, all of the widely-used formulas on how to calculate max heart rate only take into consideration your age and sometimes your sex.

While your age and sex are the two factors that most significantly impact your maximum heart rate, there are other additional factors.

The primary factors that affect your maximum heart rate include:

  • Age: Your maximum heart rate decreases with age. 
  • Genetics: Your genes can influence your MHR.
  • Body size: Although not true across the board, people with a smaller body size tend to have a higher maximum heart rate because the heart muscle is smaller.
  • Sex: Again, although not true in all cases, women tend to have a lower maximum heart rate than men, according to the American College of Cardiology.1Casteel, B. (2014, March 27). The Heart Responds Differently to Exercise in Men vs. Women. American College of Cardiology. https://www.acc.org/about-acc/press-releases/2014/03/27/12/29/allison-peak-hr-pr#:~:text=The%20study%20also%20showed%20that
  • Altitude: Being at altitude can depress your maximum heart rate.
  • Fitness level: If you are doing a field test or laboratory test to measure your max heart rate rather than estimate it with an equation, it might be challenging to achieve an actual maximum if you aren’t fit or accustomed to the type of exercise you’re doing.

For example, If you are doing a graded treadmill run and have never run, fatigue in your legs or mental/physical discomfort might force you to voluntarily stop early before you reach your true max.

A person looking at their heart rate data on a phone.

How to Calculate Max Heart Rate

There are several formulas for calculating your maximum heart rate, as researchers have continually tried to fine-tune the accuracy of MHR equations based on further testing and more data.

Some of the most common formulas for how to calculate max heart rate are as follows:

Fox Formula

The most common formula for calculating max heart rate is also the simplest: 220 minus age in years.

For example, if you’re 36, 220-36 = 184 bpm.

This formula can be used for both men and women and is typically the MHR formula used by fitness watches and exercise machines that calculate your target heart rate zones based on age.

However, while this way of calculating maximum heart rate is simple, it’s not remarkably accurate.

Despite its popularity, research indicates2Arena, R., Myers, J., & Kaminsky, L. A. (2016). Revisiting age-predicted maximal heart rate: Can it be used as a valid measure of effort? American Heart Journal173, 49–56. https://doi.org/10.1016/j.ahj.2015.12.006 that the standard deviation of the maximum heart rate equation of 220 – age in years is +/- 12 heart beats per minute.

A heart drawn on a chalkboard.

Gulati Formula

The Gulati formula for max heart rate was developed specifically for women after researchers3Sydó, N., Abdelmoneim, S. S., Mulvagh, S. L., Merkely, B., Gulati, M., & Allison, T. G. (2014). Relationship Between Exercise Heart Rate and Age in Men vs Women. Mayo Clinic Proceedings89(12), 1664–1672. https://doi.org/10.1016/j.mayocp.2014.08.018 consistently noted that the Fox Formula generally overestimates MHR for women.

This formula for calculating max HR is for women only: 206 – (0.88 × age).

HUNT Formula

The HUNT Fitness Study4Nes, B. M., Janszky, I., Wisløff, U., Støylen, A., & Karlsen, T. (2013). Age-predicted maximal heart rate in healthy subjects: The HUNT fitness study. Scandinavian Journal of Medicine & Science in Sports23(6), 697–704. https://doi.org/10.1111/j.1600-0838.2012.01445.x measured the maximum heart rate in 3,320 healthy adults aged between 19 and 89. The data was then used for a regression analysis to find the line of best fit.

The formula that describes the trend line for maximum heart rate based on age is 211 – (0.64 x age).

The HUNT formula for max HR is said to be better for active men and women, and the researchers found it to be more accurate than 220 – age or other common formulas for calculating maximum heart rate.

That said, the error margin is still about 10.8 beats per minute.

A person reading their max heart rate data.

Tanaka Formula

The Tanaka formula for calculating max heart rate is primarily designed for men and women over 40 because the traditional 220-age formula tends to have higher errors for older adults. 

This formula is 208 – (0.7 × age).

Other Max Heart Rate Formulas:

According to researchers,5Shargal, E., Kislev-Cohen, R., Zigel, L., Epstein, S., Pilz-Burstein, R., & Tenenbaum, G. (2015). Age-related maximal heart rate: examination and refinement of prediction equations. The Journal of Sports Medicine and Physical Fitness55(10), 1207–1218. https://pubmed.ncbi.nlm.nih.gov/25389634/ a more accurate estimation than the Fox Formula for max heart rate can be found through the following formulas:

  • Maximum Heart Rate for Males = 208.609-0.716 x age 
  • Maximum Heart Rate for Females = 209.273-0.804 x age

For example, if you’re a 36-year old male: 208.609-0.716 x 36 = 183 bpm. If you’re a 36-year old female: 209.273-0.804 x 36 = 180 

Another study came to the max HR equation of 209.3 – 0.72 x age, but this formula still had an error of +/- 11.8 bpm.

A person doing a laboratory test a way of how to calculate max heart rate.

How Can I Determine My Maximum Heart Rate For Effective Training?

The gold standard for measuring your maximum heart rate is to do a graded maximum exercise test in a laboratory setting.

However, another way to calculate max heart rate is by doing a field test on your own.

This will also involve pushing yourself to your maximum capacity, which takes a lot of motivation and hard work. Still, it is essentially free and probably much more accurate than relying on one of the MHR equations.

Because a max heart rate field test requires true maximum exertion, it is advisable to speak with your healthcare provider before doing the test if you are over the age of 40 and/or have any underlying medical conditions.

Once you have medical clearance and feel confident in your physical health, you just need a heart rate monitor.

Theoretically, you can measure your max heart rate using any type of cardio exercise, such as running, biking, rowing, or climbing stairs. However, running is usually the easiest way for most people to find their true maximum heart rate.

With the other forms of exercise, particularly cycling and rowing, localized muscle fatigue (tired legs or arms) can force you to lower your training intensity and stop early rather than reach your actual cardiovascular maximum.

100 Meter Sprint Max Heart Rate Field Test

  1. Warm up by running 1-3 miles, depending on your fitness level.
  2. Run one mile on a track at tempo pace, but with 400 meters to go, ramp up to an all-out effort. 
  3. Sprint the last 100 meters as fast as possible.
  4. Review your heart rate data from the last 400 meters; the highest number of beats recorded is your maximum heart rate.

Another good field test for measuring your maximum heart rate is as follows:

Ramp Up Max Heart Rate Field Test

  1. Warm up by jogging for 10-15 minutes. 
  2. Run one mile at tempo pace or a pace that you could hold for 10K or 45-60 minutes of running.
  3. Without stopping when your mile is over, increase your pace by 2 seconds per 200 meters every single 200 meters until you cannot run faster. Note that if you are running on a 400-meter track, this means you will want to run each half lap 2 seconds faster than the previous half lap until you can no longer increase your running pace. 
  4. The peak heart rate that gets displayed on your heart rate monitor before you have to slow down is your maximum heart rate.

Let’s give a practical example here. If you can run 10K in 50 minutes, your pace is 8 minutes per mile or 5 minutes per kilometer.

So your first tempo mile (four laps of the track) should be run in 8 minutes, with each lap taking 2 minutes.

When you begin the ramp-up portion of the test, your first 200 meters (half lap) should be run in 58 seconds, and the second 200 should be run in 56 seconds, for a total lap time of 1:54.

Without stopping, you move into your next 200 meters, which you should run in 54 seconds. The second half of the track should be covered in 52 seconds, and so on.

You can slow down and stop as soon as you can’t run faster.

A person looking at their watch.

If you don’t have access to a track but do have a GPS running watch, you can replicate this same protocol by increasing your pace by 20 seconds per mile every minute you run after the tempo mile.

For example, the same runner would start at an 8 min/mile pace and then increase their speed to 7:40 min/mile for the first minute, 7:20 min/mile the second minute, 7:00 min/mile the third minute, and so on until you cannot run faster.

For runners who are more comfortable dealing with distances in kilometers, you can increase your pace by 15 seconds per kilometer every minute.

Why Is It Important To know My Maximum Heart Rate?

Depending on your fitness goals, it might be fine to calculate your max HR from a formula, but it’s important to keep in mind that these calculations clearly have large margins of error.

Most heart rate calculator formulas for max heart rate6SHOOKSTER, D., LINDSEY, B., CORTES, N., & MARTIN, J. R. (2020). Accuracy of Commonly Used Age-Predicted Maximal Heart Rate Equations. International Journal of Exercise Science13(7), 1242–1250. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7523886/ have a variability of at least 10 to 12 bpm.

Therefore, your heart rate training zones can all be shifted up or down depending on where your true maximum heart rate falls relative to age-matched peers.

If you want to be as scientific as you can about your training and target zones, it’s worth the time and effort to measure your maximum heart rate with a field or laboratory test with a cardiologist.

A person getting ready for a lab test by placing sensors on their chest.

Learning how to calculate max heart rate is most valuable for runners or other athletes who notice a discrepancy between your heart rate during exercise and your perceived exertion or effort level.

This is a sign that you’re probably one of the outliers for whom the max HR equations don’t accurately estimate your maximum heart rate.

For example, if you are a runner in decent shape trying to stay within the aerobic zone for your workouts—defined to be 70-80% of your maximum heart rate—but find that your heart rate is way faster than it “should” be based on how your heart rate zones are defined, you might have a maximum heart rate that is 10-12 beats per minute faster than the mean value described by the formula you used to calculate max HR.

By measuring your actual maximum heart rate, you can shift your heart rate zones up to where they should be, giving you a better workout and a more accurate way to guide your exercise prescription, exercise intensity, training and effort.

Are you interested in more heart rate metrics and data? Check out our guides on how to calculate your heart rate zones, heart rate reserve (HRR), and resting heart rate.

Two people checking their running watches.

References

Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

2 thoughts on “How To Calculate Max Heart Rate: 8 Ways To Measure It”

  1. Thank you for this article. I’m a 40 year old woman and recently started monitoring my heart rate while running and felt frustrated because my perceived exertion didn’t match up. My heart rate is much higher than it’s “supposed to be”. I’m looking forward to testing my max heart rate on my own. I initially began monitoring my HR because my nervous system is very sensitive and my nature is to train too hard without adequate rest and my body would get run down. I was planning to use my HR to help guide me–but instead I feel like it completely sidelined me. I was feeling concerned that there’s something wrong with my heart (even tho I’m healthy and extremely conscious about living a healthy lifestyle), but I feel reassured by your article. Thank you!

    Reply
    • I have the same issue. I started tracking my heart rate yesterday. I went on a 30-minute jog, and my watch told me I was at 97% max heart rate for the entire 30 minutes. It wasn’t a particularly challenging jog. I’m also not very good at jogging. I wasn’t running very fast. I’m guessing my max heart rate is genetically high.

      Reply

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