Predicted maximum heart rate and training-zone guide
Estimate five exercise heart-rate zones with the Tanaka or 220-minus-age maximum-heart-rate equation and either percentage-of-maximum or heart-rate-reserve calculations.
This page provides an equation-based estimate for education and planning. It does not diagnose a condition, measure an individual response, or replace professional care.
How to use this health calculator
- Choose appropriate inputs: Enter measurements using the units and ranges shown.
- Review the assumptions: Confirm that the model applies before interpreting the result.
- Calculate and interpret: Read the result together with its limitations and cautions.
- Use professional guidance when needed: Do not use a general calculator to change medication, treatment, or a clinician-directed plan.
Formula and variables
The selected equation predicts maximum heart rate from age. Zone boundaries then use either fractions of that prediction or the Karvonen-style heart-rate-reserve calculation.
HRmax = 208 − 0.7×age or 220 − age; reserve zone = resting HR + (HRmax − resting HR) × intensity- HRmax — Predicted maximum heart rate
- Age-based population estimate, not a measured maximum.
- HRrest — Resting heart rate
- Pulse measured while awake, calm and at rest.
- I — Intensity fraction
- Selected fraction from 0.50 through 1.00.
Worked example: heart-rate reserve
A 40-year-old with resting heart rate 60 bpm uses the Tanaka equation.
- Age
- 40 years
- Resting heart rate
- 60 bpm
- Method
- Heart-rate reserve
- Predicted maximum = 208 − 0.7×40 = 180 bpm.
- Reserve = 180 − 60 = 120 bpm.
- 50% boundary = 60 + 120×0.50 = 120 bpm.
Result: The modeled Zone 1 lower boundary is 120 bpm.
The boundary is an estimate; perceived exertion, symptoms and qualified guidance remain important.
Understanding your results
Equation result
The numerical output follows the displayed formula and entered assumptions.
Personal interpretation
Individual biology, measurement error, environment, health conditions and medicines can change real-world outcomes.
Assumptions
- Age is within the adult input range.
- Resting heart rate is measured under calm conditions.
- The selected equation and zone scheme are appropriate for general planning.
Limitations
- Predicted maximum can differ substantially from measured maximum.
- Zone systems use different labels and boundaries.
- Medication, illness, heat, fitness and cardiovascular conditions can alter response.
Common mistakes
- Treating predicted maximum as a measured value.
- Using an exercise pulse as resting heart rate.
- Ignoring symptoms or perceived exertion.
- Assuming one zone scheme applies to every training plan.
Practical use cases
Educational estimate
Explore how the inputs affect the equation result.
Consistent tracking
Compare estimates only when methods, units and conditions are consistent.
Planning and decision guide
Treat cautions as part of the result
The American Heart Association presents target ranges as general guides and advises gradual progression.
People with cardiovascular disease, symptoms or heart-rate-altering medicines should seek individualized exercise guidance.
Escalate symptoms or clinical questions
Seek qualified medical advice for symptoms, diagnosed conditions, medicines, pregnancy, or individualized treatment decisions.
Frequently asked questions
Which maximum-heart-rate equation is exact?
Neither is exact for an individual; both are age-based predictions.
Why does heart-rate reserve need resting pulse?
It scales intensity across the difference between resting and predicted maximum heart rate.
Should I exercise at 100%?
This calculator displays arithmetic zone boundaries, not a recommendation to perform maximal exercise.
Sources and review
- Age-predicted maximal heart rate revisited — Journal of the American College of Cardiology (PubMed). Accessed 2026-08-03.
- Target Heart Rates Chart — American Heart Association. Accessed 2026-08-03.
Reviewed 2026-08-03.