Target heart rate calculator
The Karvonen method works from heart rate reserve rather than raw maximum, which matters a lot if your resting rate is unusually high or low.
bpm
bpm
%
Target heart rate
148bpm
- Heart rate reserve
- 125 bpm
- As a share of maximum
- 79.7 %
Show the working
- Maximum heart rate = 185
- Resting heart rate = 60
- Target intensity = 70
- Heart rate reserve = 185 - 60 = 125
- Target heart rate = 60 + 125 * 70 / 100 = 147.5
- As a share of maximum = 147.5 / 185 * 100 = 79.7297
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
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The formula
- target = resting + intensity x (HRmax - resting)
A Karvonen 70% is a higher absolute rate than a plain 70% of maximum, which catches people out.
This is a population formula, not a diagnosis. Individual metabolism, body composition and medical history all move the real answer, so treat the number as a starting point and talk to a clinician about anything that matters.