The Karvonen formula is the most accurate method for determining your heart rate.

To determine target heart rate using the Karvonen formula

  • Subtract age from 220 to get Maximum Attained Heart Rate (MAHR)
  • Subtract Resting Heart Rate (RHR) from MAHR to get Heart Rate Reserve (HRR)
  • Multiply HRR by exercise intensity and then add RHR to get Target Heart Rate (THR)

The Karvonen method for determining training heart rate is superior to the traditional method of simply subtracting age from 220 and then multiplying by the level of intensity of the workout to determine your target heart rate. The Karvonen formula takes into account resting heart rate to determine the Heart Rate Reserve.

Since resting heart rate is reduced as the level of conditioning improves the Karvonen formula is a more accurate method for determining Training Heart Rate.  As resting heart rate goes down the Heart Rate Reserve – the difference between Resting Heart Rate and Maximum Heart Rate – increases, and is a reflection of the heart’s increased efficiency in pumping blood.

For example, use the Karvonen formula for a 40-year old client with a Resting Heart Rate of 65.

  • 220 – 40 = 180 MAHR
  • 180 – 65 = 115 HRR
  • 115 * 80% = 92 + 65 = 157 THR

For the same person, look at the Target Heart Rate using the old school, simple method.

  • 220 – 40 = 180 MAHR
  • 180 * 80% = 144 THR

Using the traditional method for determining Target Heart Rate puts you well below your capacity for work and using this lower heart rate as a guide results in a less effective and efficient workout. Take your Resting Heart Rate before getting out of bed in the morning for three consecutive days and use the average in this calculation.


  1. I am 70 years old – so to take these numbers I have 220 -70+ 150 resting heart rate is 50 + 100 X 80 + 65 + 145 – no way can I sustain that for my target rate – I routinely work out and usually keep my heart rate in the range of 110 – 122 – but can’t keep it in the 145 range – in fact that’s been viewed as my max rate –

  2. Steve
    That calculation you did is at a higher intensity, an intensity that you wouldn’t necessarily shoot to maintain for a long period of time. If you apply 60-70% to the calculation you get a training heart rate of 110-120. Also it appears you
    subtracted your resting heart rate of 50 but added my example of 65 as a resting heart rate rather than yours.
    According to my calculations, I get a 130 training heart rate for you at 80%.
    I’m not a math whiz (!) but I think that’s where you are confused…Am I right?


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