What is the Karvonen formula?

The Karvonen formula applies intensity to heart rate reserve, which is estimated maximum heart rate minus resting heart rate, then adds resting heart rate back to the result.

Is target heart rate the same for everyone my age?

No. Age-based charts are averages. Resting heart rate, fitness, medication, heat, stress, hydration and medical conditions can all change the right range.

Can I use this if I take beta-blockers?

Use it only as background information. Beta-blockers and other medicines can lower exercise heart rate, so a clinician may recommend different targets.

Target Heart Rate Calculator

Calculate an estimated target heart rate range from age, resting heart rate, intensity and max-heart-rate method, with Karvonen and percent-max options.

Age

Resting heart rate, bpm

Measure when calm, ideally in the morning, and average several days.

Maximum heart rate

The Tanaka age estimate is a starting point; a lab test or clinician-provided value is more specific.

Target heart rate method

Karvonen uses resting heart rate and heart rate reserve. Percent of max HR is simpler but less individualized.

Intensity from, %

Intensity to, %

Target heart rate range

This calculator matches the English target heart rate intent: estimate a heart-rate range for a chosen exercise intensity, compare Karvonen heart-rate reserve with percent of maximum heart rate, and show where the result sits within common training zones.

HR_{ma x} = 208 - 0.7 \times a g e

Tanaka age-predicted maximum heart rate estimate.

THR = HR_{r es t} + I \times (HR_{ma x} - HR_{r es t})

Karvonen heart-rate reserve target heart rate.

Safety and interpretation

The American Heart Association presents target zones as general averages, often about 50% to 85% of estimated maximum heart rate.
The CDC talk test is useful alongside numbers: moderate intensity usually allows talking but not singing; vigorous intensity makes speaking more than a few words difficult.
Heart disease, pregnancy, beta-blockers and other medicines that affect pulse can make formula zones unsuitable without clinician guidance.

Not an exercise prescription

Do not treat the result as medical clearance or a guaranteed safe heart-rate limit. Stop exercise and seek medical evaluation for chest pain, severe shortness of breath, dizziness or unusual weakness.

Frequently Asked Questions

Sources and References

Calculations are based on the listed reference sources. Links open in a new tab.

Updated: June 2, 2026

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