Target Heart Rate Zone Calculator
Calculate your five cardio training zones using the Karvonen formula — based on your age and resting heart rate.
About this calculator
This calculator uses the Karvonen formula to map your five cardiovascular training zones. Maximum heart rate is estimated as 220 minus your age. Heart Rate Reserve (HRR) is the difference between your max and resting heart rate — it represents your usable cardiovascular range. Each zone is computed as a percentage of HRR added back to your resting rate: Target HR = (HRR × intensity%) + Resting HR. Because resting heart rate is accounted for, the Karvonen method is more personalized than a simple percentage-of-max approach.
Field explanations
- Age
- Used to estimate maximum heart rate (220 − age). A 30-year-old has an estimated max HR of 190 bpm.
- Resting heart rate
- Your heart rate at complete rest, measured in beats per minute. For best accuracy, measure first thing in the morning before getting out of bed. Typical adult range is 60–100 bpm; trained athletes may be 40–60 bpm.