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Miraç Özdemir
Sports & Exercise

Target Heart Rate Zone Calculator (Karvonen)

Estimate your maximum heart rate from your age and the target heart rates for 50–100 % intensity, optionally with your resting heart rate using the Karvonen method.

Version 3

Things to keep in mind:

  • Age-based formulas are population averages; an individual maximum heart rate can differ by ±10–12 bpm or more. The most accurate value comes from a medically supervised exercise test.
  • Heart rate zones do not apply to people taking heart-rate-lowering medication such as beta blockers, people with heart disease or during pregnancy; agree on exercise intensity with your doctor.
  • The formulas have not been validated for children and adolescents.
  • Stop exercising immediately and seek medical help if you have chest pain, dizziness or severe shortness of breath.
  • The result is an estimate, not a medical diagnosis or treatment advice; consult your physician or dietitian for decisions about your health.

Calculator

Heart rate details

Your age in whole years (15–100).

Maximum heart rate formula

The Tanaka (2001) formula was found more accurate than 220 − age, especially at older ages.

Zone method

The Karvonen method also takes your resting heart rate into account.

After the first calculation, the result updates automatically when you change a value.

Result

Enter the values and press Calculate to see the result here.

About this tool

Target heart rate zones are used to monitor exercise intensity by heart rate. The calculator first estimates your maximum heart rate from your age, then the heart rates for 50, 60, 70, 80, 90 and 100 % intensity with the method you choose.

Maximum heart rate

  • Fox: max HR = 220 − age
  • Tanaka, Monahan and Seals (2001): max HR = 208 − 0.7 × age

Zone methods

  • Percentage of maximum: target = max HR × intensity
  • Karvonen (1957), heart rate reserve: reserve = max HR − resting HR; target = resting HR + reserve × intensity

Zones are commonly read as: 50–60 % very light/warm-up, 60–70 % light (fat burning and base endurance), 70–80 % moderate (aerobic), 80–90 % hard (threshold), 90–100 % maximal effort. A zone is the range between two neighbouring percentage values.

Example: for a 40-year-old with a resting heart rate of 60, the Tanaka formula gives 208 − 28 = 180 bpm. The heart rate reserve is 180 − 60 = 120; with Karvonen, 60 % intensity is 60 + 0.6 × 120 = 132 bpm and 80 % is 156 bpm.

Example 2 (comparing methods): for a 40-year-old the Tanaka formula gives a maximum heart rate of 180 bpm. With the "percentage of maximum" method, 60 % intensity is 108 bpm and 80 % is 144 bpm. With a resting heart rate of 60 and the Karvonen method, the same intensities are 132 and 156 bpm; the higher the resting heart rate, the higher the Karvonen values sit. At age 60 the Fox formula gives 160 bpm and Tanaka 166 bpm; the formulas diverge more at older ages.

How to read the result: "Estimated maximum heart rate" is an age-based population average; your true maximum can differ by ten beats or more. The 50–100 % rows are the estimated heart rates at those intensities; the range between two neighbouring values indicates a zone. Heart rate reserve is calculated only with the Karvonen method and is the difference between maximum and resting heart rate. These values are a general reference; ask your doctor or coach for personal decisions and programmes about exercise intensity.

How to use

  1. Enter your age.
  2. Choose the maximum heart rate formula.
  3. Choose the zone method; for Karvonen enter your resting heart rate.
  4. Press Calculate.

Notes

Heart rates are in beats per minute (bpm), rounded to whole numbers (HALF_UP); zones are computed from the unrounded maximum heart rate. The heart rate reserve is only shown with the Karvonen method; otherwise it is 0.

Sources

References

  1. [1]
    Age-predicted maximal heart rate revisitedTanaka H, Monahan KD, Seals DR, J Am Coll Cardiol, 2001

Frequently asked questions

4 questions

  1. The best-known formula is 220 − age. The Tanaka formula (208 − 0.7 × age) is based on a larger dataset and is considered more accurate, especially over 40.

Next step

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