Target Heart Rate Calculator

What is heart rate

Three related numbers drive every calculation on this page:

• Maximum heart rate (MHR). The highest number of beats per minute your heart can reach during maximal exertion. It is rarely measured directly outside a supervised exercise test, so it is almost always estimated from age using one of several published formulas, three of which this calculator lets you choose between.
• Resting heart rate (RHR). Your heart rate at complete rest, most reliably measured first thing in the morning before getting out of bed. A lower resting heart rate is generally associated with better cardiovascular fitness.
• Heart rate reserve (HRR). The gap between the two: maximum heart rate minus resting heart rate. This is the number the Karvonen method uses instead of maximum heart rate alone, which is why it produces noticeably different training zones for people with the same age but different resting heart rates.

There is no single official way of how to determine maximum heart rate outside a supervised lab test, which is why most people rely on an age-based formula instead. That is also why this page works as a max heart rate calculator or a maximum heart rate calculator in its own right, before it goes on to build a full target heart rate zone table, and why so many searches for how to find max heart rate land on a formula-based estimate like the three below rather than a treadmill test. Because maximum heart rate is estimated from age, these heart rate zones for age update automatically the moment you change the age field above. Maximum heart rate itself has three named, published age-predicted formulas available on this calculator:

• Haskell & Fox: The classic, most widely referenced formula, and this calculator's default.
  MHR = 220 - age
• Tanaka, Monahan & Seals (2001): Built from a broader, more recent research sample; tends to predict a slightly higher maximum heart rate for older adults than Haskell & Fox.
  MHR = 208 - 0.7 × age
• Nes, Janszky, Wisloff, Stoylen & Karlsen (2013), the HUNT formula: From the HUNT Fitness Study, a large Norwegian cohort; a third, more recent alternative.
  MHR = 211 - 0.64 × age

Worked example. For a 30 year old, Haskell & Fox gives 220 − 30 = 190 bpm, Tanaka gives 208 − 0.7 × 30 = 187 bpm, and Nes gives 211 − 0.64 × 30 = 191.8, rounding to 192 bpm. All three describe the same person; the 5 bpm spread between the lowest and highest is a realistic sense of how much these formulas can disagree at the same age.

Target heart rate zones: how the target heart rate calculator sets them

Once maximum heart rate is known, here is how to calculate heart rate zones: exercise physiologists commonly split the range below it into five named intensity zones, from Very light to Very Hard, each expressed both as a percentage of maximum heart rate and as a percentage of heart rate reserve. This calculator shows this 5-tier, color-coded table automatically once you enter your age and resting heart rate, using whichever maximum heart rate formula you selected:

• Very light: under 57% of max heart rate, under 30% of heart rate reserve.
• Light: 57 to 63% of max heart rate, 30 to 39% of heart rate reserve.
• Moderate: 64 to 76% of max heart rate, 40 to 59% of heart rate reserve.
• Hard: 77 to 93% of max heart rate, 60 to 89% of heart rate reserve.
• Very Hard: 94 to 100% of max heart rate, 90 to 100% of heart rate reserve.

These five bands are a more granular breakdown of the same idea behind the four-zone Light/Moderate/Vigorous/Very-vigorous tables further down this calculator; both are legitimate ways to slice the same percent-of-max or percent-of-reserve range, just at different resolutions. Different goals call for different target heart rates: the Hard and Very Hard tiers line up with a typical aerobic exercise heart rate goal for building cardio fitness, while the aerobic heart rate zone most people mean by easy base training sits closer to Moderate. Whichever tier you are aiming for, these are the same cardio heart rate zones referenced throughout the rest of this page.

The simple percent-of-max method explained

The simple method starts from one number, your estimated maximum heart rate, and takes a percentage of it for each training zone. Maximum heart rate is estimated with the classic formula 220 − age, which became the standard shorthand from older population research and remains the figure most gyms, trainers and fitness devices reference today. Each zone is then just a percentage band of that one number, for example the Vigorous (cardio) zone at 70 to 85 percent of maximum heart rate.

The honest limitation of this formula is that it is a population average, not a personal measurement. Individual variation of plus or minus 10 to 12 beats per minute around the 220-minus-age estimate is well documented, so two people of the same age can have genuinely different true maximum heart rates even though the formula assigns them the same number. It is a useful starting estimate for general training, not a substitute for a supervised maximal exercise test.

The Karvonen method explained

The Karvonen method adds one more input, resting heart rate, and uses it to build a more personalized zone. Instead of taking a percentage of maximum heart rate directly, it first works out the heart rate reserve:

Then it takes a percentage of that reserve and adds resting heart rate back in:

The result is that someone with a lower resting heart rate, often a sign of better cardiovascular fitness, is given noticeably higher target zones than the simple method would suggest, because more of their heart's working range counts toward the calculation.

Worked example. A 30 year old with a resting heart rate of 65 bpm has a maximum heart rate of 220 − 30 = 190 bpm. The simple method puts their Moderate (fat burn) zone, 60 to 70 percent of maximum heart rate, at 114 to 133 bpm. The Karvonen method instead starts from the heart rate reserve, 190 − 65 = 125 bpm, takes 60 to 70 percent of that reserve, 75 to 87.5 bpm, and adds back the resting heart rate of 65, giving a Moderate zone of 140 to 153 bpm. Both numbers describe the same "moderate" effort level, but the Karvonen range sits noticeably higher, because it accounts for this person's below-average resting heart rate rather than treating them the same as anyone else their age.

Methods for measuring exercise intensity

The Haskell & Fox zone method and the Karvonen method above both estimate intensity from heart rate. Two other widely used methods estimate intensity from how hard an activity feels, without needing a heart rate reading at all, which makes them useful when checking your actual heart rate during workout sessions by hand is inconvenient, or when heart rate itself is affected by medication or heat.

The Borg RPE scale (6 to 20)

The Borg Rating of Perceived Exertion (RPE) scale runs from 6 to 20, deliberately starting at 6 rather than 0 or 1, so that multiplying a rating by 10 gives a rough estimate of heart rate for a healthy adult during exercise: 6 × 10 = 60 bpm (a typical resting heart rate), 20 × 10 = 200 bpm (close to a young adult's maximum).

• 6: No exertion at all
• 9: Very light
• 11: Light
• 13: Somewhat hard
• 15: Hard
• 17: Very hard
• 19: Extremely hard
• 20: Maximal exertion

Worked example. Someone who rates their effort a 13 ("Somewhat hard") has an estimated heart rate of 13 × 10 = 130 bpm. This is a rough heuristic built for a general adult population, not a substitute for an actual pulse reading, but it is useful precisely because it needs no equipment at all, just a subjective sense of effort.

The modified Borg CR10 scale (0 to 10)

The Borg CR10 (Category-Ratio 10) scale is a separate, non-linear scale, built to describe perceived exertion and breathlessness directly rather than to approximate heart rate, so it has no rating-times-10 shortcut the way the 6-20 RPE scale does.

• 0: Nothing at all
• 0.5: Extremely weak
• 1: Very weak
• 2: Weak
• 3: Moderate
• 4: Somewhat strong
• 5: Strong
• 7: Very strong
• 10: Extremely strong (almost maximal)

Worked example. A runner who describes their breathing and leg effort during a tempo run as a 5 ("Strong") on the CR10 scale is reporting a meaningfully harder effort than a 3 ("Moderate"), but the CR10 scale does not translate that 5 into any specific bpm figure the way an RPE of 13 translates to roughly 130 bpm; the two scales are related in concept but are not interchangeable number for number.