The heart rate calculator estimates maximum heart rate and moderate to vigorous target ranges using age-based formulas. It can also show a Karvonen heart-rate-reserve range when resting heart rate is supplied.
How to use this calculator
Enter age and an optional resting heart rate. Maximum heart rate uses 208 minus 0.7 times age. Standard target percentages are applied to that maximum, while the reserve method adds the selected fraction of heart-rate reserve to resting heart rate.
Formula & calculation method
Estimated HRmax = 208 − 0.7 × age; HRR = HRmax − resting HRModerate intensity is shown as 50–70% and vigorous as 70–85% of estimated maximum. Karvonen ranges use the same percentages of reserve plus resting heart rate. These are general exercise-guideline calculations, not individualized prescriptions.
Worked example
At age 30, the formula estimates HRmax as 187 beats per minute. A 50–70% range is about 94–131 bpm before considering resting heart rate or personal exercise limitations.
Why this is useful
Multiple ranges help explain the difference between simple maximum-percentage and reserve methods. The calculator makes its formula explicit so users can compare it with guidance from a coach or healthcare professional.
Limitations to keep in mind
Age-predicted maximum varies substantially between individuals. Medications, cardiovascular conditions, fitness, and symptoms can affect safe exercise intensity. Stop exercise and seek appropriate help for concerning symptoms, and consult a professional when needed.
Frequently asked questions
How accurate is the maximum heart-rate estimate?
It is a population formula with individual variation. A measured, professionally supervised assessment is different from an age-based prediction.
What is heart-rate reserve?
It is estimated maximum heart rate minus resting heart rate. The Karvonen method applies intensity percentages to that reserve.
Can I use it while taking heart medication?
Some medications change heart-rate response, making generic ranges inappropriate. Ask a qualified clinician for individualized guidance.