Heart Rate Zones Calculator
5-zone HR training calculator using the Karvonen formula with zone descriptions and training applications.
Inputs
Fill in the inputs and press Calculate to see your science-backed results.
How to use Heart Rate Zones Calculator
5-zone HR training calculator using the Karvonen formula with zone descriptions and training applications.
Choose measurements that describe your actual session or situation, confirm the units, then calculate. Read the result alongside its assumptions and use the tool again when your inputs change.
Inputs explained
Age
Enter a measured or estimated value (minimum 12) (maximum 100), using the unit indicated in the field label.
Resting HR (bpm)
Enter a measured or estimated value (minimum 35) (maximum 100), using the unit indicated in the field label.
Max HR (bpm, optional - leave 0 for estimate)
Enter a measured or estimated value (minimum 0) (maximum 220), using the unit indicated in the field label.
Sex
Choose the option that matches your context; available options include Male, Female.
Fitness level
Choose the option that matches your context; available options include Low, Moderate, High.
How to interpret the output
Keep testing conditions and intensity consistent. Estimates from field tests do not replace laboratory assessment.
Repeat measurements using similar conditions when monitoring trends. Numerical predictions can vary with input accuracy, measurement method and individual circumstances.
Limitations and responsible use
Age-predicted max HR (220-age) has wide individual variation. A field test provides a more accurate max HR.
Read the full disclaimerFrequently asked questions
What does the Heart Rate Zones Calculator estimate?
5-zone HR training calculator using the Karvonen formula with zone descriptions and training applications.
Which information do I need for this cardio tool?
Provide Age, Resting HR (bpm), Max HR (bpm, optional - leave 0 for estimate), Sex, Fitness level. Use your own relevant measurements and the units indicated in each field.
How should I interpret the result?
Keep testing conditions and intensity consistent. Estimates from field tests do not replace laboratory assessment. Compare results with your goals and other relevant observations rather than using a single output to make a major decision.
Disclaimer: Age-predicted max HR (220-age) has wide individual variation. A field test provides a more accurate max HR. Read the medical disclaimer.
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