Heart rate zones calculator
HealthCalculate your five training heart rate zones from age and resting heart rate using Karvonen or percent of max.
Your results
Calculate your five training zones from age and resting heart rate.
How zones are calculated
Maximum heart rate is estimated as 220 minus age. Karvonen uses the heart rate reserve (maxHR - restingHR) added to restingHR; percent of max uses maxHR directly.
Which method is better?
Karvonen is generally more accurate for trained people because it includes resting heart rate. Percent of max is simpler and works fine for casual training.
Frequently asked questions
Answers to the most common questions about this tool.
How is this result calculated?
It uses the method and inputs described on this page to provide an informational estimate.
How accurate is the result?
It is an estimate and should be interpreted as a guide, not an exact measurement.
When should I seek professional advice?
Seek qualified advice for symptoms, pregnancy, illness, medication use, or clinical decisions.
What information do I need to enter?
Enter current, accurate details and select the correct units before calculating.
What can affect this estimate?
Individual factors such as health, activity, body composition, and measurement technique can affect it.
Sources and methodology
Methodology: Heart-rate zones
Estimates maximum HR as 220 − age and calculates zones by percent maximum HR or Karvonen heart-rate reserve.
The 220 − age formula and zone boundaries are ToolsRL simplifications.
References
Last reviewed
July 15, 2026