What this tool does
The calculator estimates max heart rate, builds Zone 1 to Zone 5 ranges, and uses heart-rate reserve when resting heart rate is provided.
How to use it
- Enter your age.
- Optionally enter resting heart rate to get heart-rate reserve zones.
- Use the ranges as a general training estimate.
- If you have clinician-set limits, follow those instead of a generic calculator.
Important limitations
These numbers are planning estimates, not a diagnosis or individualized medical advice. They can be less appropriate during pregnancy, breastfeeding, adolescence, illness, recovery from an eating disorder, or when a clinician has given you specific nutrition instructions.
Frequently asked questions
What if I do not know my resting heart rate?
Leave it blank. The calculator will use percentages of estimated max heart rate instead.
Are these zones exact?
No. They are training estimates, not medical limits and not lab-tested thresholds.
Why can resting heart rate not be above max heart rate?
That would make the formula invalid, so the input is blocked.