Diastra Max heart rate · Part 1 of 4
Max heart rate calculator
Find your max heart rate and zones
Type your age to see the estimate. Type a max you have seen in a race or a hard effort and every band redraws from it.
Age 35 · max heart rate 208 − 0.7 × 35 = 184, an estimate
Your Easy band, your Zone 2111 to 146beats a minute
Your Easy band runs 16 beats higher than the common Zone 2 chart lets you go.
Max from age uses Tanaka’s formula (208 − 0.7 × age). Easy ends where blood tests find lactate starting to rise, which is higher for women than for men. What you type stays on this page.
Diastra reads your max from your own Apple Watch workouts or a guided test and draws your bands from it.
Start my free trialA review of 351 studies with 18,712 people found that maximum heart rate averages 208 minus 0.7 times your age, so the estimate for a 40-year-old is 180 beats a minute. People the same age are often about 10 beats above or below that estimate, so a max you have seen in a race or a hard effort is a better number to train from.
On this page
What is max heart rate?
Your max heart rate is the most times your heart can beat in a minute. You reach it only at the very end of an all-out effort, like the last stretch of a hard race.
Most heart rate zone charts are built on this one number. Each zone is a percent of your max. A max that is 10 beats too high pushes every zone up with it. A max that is 10 beats too low pulls every zone down.
Your max is the top edge of the chart. It sets the edges of the bands you train in.
How does this calculator estimate your max?
The calculator uses the Tanaka formula when you leave the max blank. The formula takes 0.7 times your age away from 208.
- At 30, that is 208 minus 21, or 187 beats a minute.
- At 40, the estimate is 180.
- At 55, the estimate is about 170.
The formula comes from a 2001 study by Hirofumi Tanaka and his team.[1] They pooled 351 earlier studies with 18,712 people. Then they tested 514 healthy adults in their own lab. The lab group gave 209 minus 0.7 times age, which is almost the same line.
The same study found that men and women share one line. The line also held for active and inactive people alike.[1] A Norwegian study of 3,320 healthy adults found the same thing. Its differences by sex, activity and fitness were small.[2]
The calculator asks your sex for a different reason. Sex moves the top of the Easy band.
Blood tests on 165 recreational runners measured lactate. Your muscles release lactate faster as the effort climbs. In those runners, lactate started to rise at 78.9% of max for men and 83.6% for women on average.[8] The calculator ends Easy close to those lines, at 79% for men and 83% for women.
Many charts still use 220 minus age. The Tanaka study compared that older shortcut with its own line. The shortcut gives young adults too high a max and older adults too low a max, and the two lines meet at age 40.[1]
The max heart rate formulas page compares them side by side. The max heart rate by age chart shows both for ages 18 to 75.
How far can your real max be from the estimate?
A formula gives the average for people your age. You are one person, and one person can be far from the average.
In the Tanaka lab study, people the same age spread about 10 beats a minute above and below the line.[1] That spread is a standard deviation, which measures how far people usually are from the average. It ran from 7 to 11 beats at different ages.[1] The Norwegian study found a typical miss of 10.8 beats a minute.[2]
Another study tested 762 adults who did not exercise regularly. The Tanaka formula missed by 11.4 beats a minute on a typical person. The 220 minus age formula missed by 12.4 beats.[3] The authors concluded that age formulas do not precisely predict one person's measured max.
A smaller study checked nine common age formulas against 99 treadmill tests. Every formula showed wide gaps between the guess and the measured max.[4]
Picture two 40-year-old runners. The formula gives both of them 180. One has a real max of 170 and the other has 190. Both fall inside the usual spread.
The older 220 minus age formula can miss by even more. Tanaka's own paper warns that it could miss some older adults by more than 20 beats.[1]
Why is a measured max better?
Every band moves with the max. A miss in the max becomes a miss in every band.
Say your real max is 190 and the formula guesses 180. For a man, Easy ends at 79% of max.
From the guess, Easy ends at 142. From the real max, Easy ends at 150. The guess cuts 8 beats off the top of your easy running.
The miss can run the other way. Say your real max is 170 and the formula still guesses 180. From your real max, Easy ends at 134. The guess lets easy runs climb 8 beats past the top of your Easy band.
The bands still come from research averages. A max you have seen takes the guess out of the number they are drawn from. Type a max into the calculator above and every band redraws from it.
How do runners find their real max?
Your real max shows up only near the end of an effort where you go as hard as you can. You may already have one in your workout history. The highest heart rate from a recent race or a hard session is a good place to start.
Warm up with easy running before any all-out effort. Pick a day when you feel rested. Run on ground you know well.
A race finish
A race gives you an all-out effort with a clear finish line. One study measured 20 college distance runners three ways. Their heart rates averaged 206 in a race and 207 in a hard track session. On a lab treadmill test, the same runners averaged 194.[5]
Look for the highest heart rate you held in the final minutes of a 5K or a 10K.
Hard hill repeats
Find a steady hill that takes a few minutes to climb. Run up it hard and jog back down to recover.
Run each climb a little harder than the one before. Make the last climb all-out to the top. Your highest heart rate usually comes near the top of that last climb.
A guided field test
A guided test starts with a warm-up. Then it raises the pace in steps until you cannot go any faster. A running coach or an app can lead it. The steps take the guessing out of pacing, so you reach the end with nothing left.
Trust a number you held
Wrist sensors read less accurately than a chest strap during exercise. A 2017 study tested 50 adults on a treadmill, a bike and an elliptical. A chest strap matched the lab's heart monitor most closely, and the Apple Watch came next.[6]
A 2018 study put an Apple Watch on each wrist of 15 people during an all-out test. The watches read max heart rate well against a chest strap, and they did not read high or low on average.[7]
Trust a peak that your heart rate held for a stretch. A peak you have seen on more than one hard day is better still. If you own a chest strap, wear it for the effort.
What is your max heart rate used for?
Your max sets the edges of every training band. The calculator above draws three bands from it.
- Easy runs from 60% of max up to 79% for men and 83% for women. Easy is the pace you can hold a conversation at. If you train by Zone 2, Easy is that same easy running. Its top edge comes from blood tests on runners.[8] Zone 2 heart rate explains where the common chart stops and why.
- Threshold runs from 87 to 92% of max. It is the fastest pace you can hold before fatigue stacks up quickly. In the same blood tests, the second lactate threshold came at 90.6% of max on average.[8] That is where lactate starts to build faster than the body can clear it.
- VO₂max runs from 92% of max to the top. VO₂max is your aerobic capacity, the most oxygen your body can use when you go all-out. One study gave moderately trained men four 4-minute intervals at 90 to 95% of max. Their VO₂max rose 7.2% in 8 weeks.[9]
The space between Easy and Threshold shows up in the calculator as Gray. It is moderate running that is harder than Easy and easier than Threshold.
Can your Apple Watch find your real max?
Your Apple Watch saves the heart rate of every workout in Apple Health. A real max may already be in there from a race or a hard session. How to find your max heart rate with an Apple Watch walks through where to look.
Diastra reads every workout your Apple Watch saved in Apple Health. It starts from the same Tanaka estimate as this calculator. When your workouts show a higher max, the number rises to match. Diastra needs a high heart rate you held in one workout and matched within 8 beats in another, so a single spike never sets your max.
A guided test can raise the number too. A max you type replaces the estimate whether it is higher or lower. Diastra says which of these your bands came from.
See your own bands from your own workouts.
Diastra reads every workout your Apple Watch saved, finds your real max heart rate and draws Easy, Threshold and VO₂max from it. Then it holds you in your band on every run and shows you over the weeks whether your training is working.
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More questions
Is a higher max heart rate a sign of fitness?
No. In the Tanaka study, active and inactive adults shared the same age line. A Norwegian study of 3,320 adults found only small differences between people with high and low fitness. Fitness shows up in VO₂max, which training can raise.
What if I never reach the estimated max?
Some runners never reach it. People the same age spread about 10 beats a minute on either side of the average, so some real maxes are well below it. A lower max says nothing about your fitness. If all-out races never take you near the estimate, type the highest heart rate you have held into the calculator above.
Why did my watch show a heart rate above my estimated max?
Your real max may be higher than the estimate. A formula gives the average for your age, and plenty of people are above it. Wrist sensors also read less accurately than a chest strap during exercise. Trust a number your heart rate held for a stretch or reached again on another hard day.
How often should I find my max again?
Not often. By the Tanaka line, the average max drops about 0.7 beats a minute each year, so a good number stays close for years. Update it when a race or a hard session shows a higher number that your heart rate held.
Sources
- Tanaka H, Monahan KD, Seals DR. 2001. Age-predicted maximal heart rate revisited. J Am Coll Cardiol 37(1):153-156.Pooled 351 studies with 18,712 people and tested 514 more in a lab. Max heart rate averaged 208 minus 0.7 times age for men and women and across activity levels, and people the same age spread about 10 beats a minute either side.
- Nes BM, Janszky I, Wisløff U, Støylen A, Karlsen T. 2013. Age-predicted maximal heart rate in healthy subjects: The HUNT fitness study. Scand J Med Sci Sports 23(6):697-704.Tested 3,320 healthy Norwegian adults. Max averaged 211 minus 0.64 times age with a typical miss of 10.8 beats a minute, and differences by sex, activity or fitness were small.
- Sarzynski MA, Rankinen T, Earnest CP, Leon AS, Rao DC, Skinner JS, Bouchard C. 2013. Measured maximal heart rates compared to commonly used age-based prediction equations in the Heritage Family Study. Am J Hum Biol 25(5):695-701.Tested 762 adults who did not exercise regularly. The typical miss was 11.4 beats a minute for the Tanaka formula and 12.4 for 220 minus age.
- Shookster D, Lindsey B, Cortes N, Martin JR. 2020. Accuracy of commonly used age-predicted maximal heart rate equations. Int J Exerc Sci 13(7):1242-1250.Checked nine age formulas against 99 treadmill tests and found wide gaps between the guessed and the measured max for every formula.
- Semin K, Stahlnecker AC 4th, Heelan K, Brown GA, Shaw BS, Shaw I. 2008. Discrepancy between training, competition and laboratory measures of maximum heart rate in NCAA division 2 distance runners. J Sports Sci Med 7(4):455-460.Measured 20 college distance runners. Heart rate averaged 206 in a race and 207 in a hard track session, against 194 on a lab treadmill test.
- Gillinov S, Etiwy M, Wang R, Blackburn G, Phelan D, Gillinov AM, Houghtaling P, Javadikasgari H, Desai MY. 2017. Variable accuracy of wearable heart rate monitors during aerobic exercise. Med Sci Sports Exerc 49(8):1697-1703.Tested 50 adults on a treadmill, a bike and an elliptical. A chest strap matched the lab heart monitor best, the Apple Watch came next, and every wrist device but one did well on the treadmill.
- Abt G, Bray J, Benson AC. 2018. The validity and inter-device variability of the Apple Watch for measuring maximal heart rate. J Sports Sci 36(13):1447-1452.Fifteen people did an all-out test with an Apple Watch on each wrist. The watches read max heart rate well against a chest strap and did not read high or low on average.
- Nuuttila OP, Kaikkonen P, Sievänen H, Vasankari T, Kyröläinen H. 2025. The accuracy of fixed intensity anchors to estimate lactate thresholds in recreational runners. Eur J Appl Physiol 125(8):2161-2171.Blood tests on 165 recreational runners found lactate starts to rise at 78.9% of max for men and 83.6% for women, and the second threshold came at 90.6% of max on average.
- Helgerud J, Høydal K, Wang E, Karlsen T, Berg P, Bjerkaas M, Simonsen T, Helgesen C, Hjorth N, Bach R, Hoff J. 2007. Aerobic high-intensity intervals improve VO2max more than moderate training. Med Sci Sports Exerc 39(4):665-671.Compared four kinds of training in 40 moderately trained men. Four 4-minute intervals at 90 to 95% of max three times a week raised VO₂max 7.2% in 8 weeks.