Karvonen Heart Rate Calculator
Calculate personalized training heart-rate zones using the Karvonen heart-rate reserve method, with max-HR formula options and zone outputs.
What the Karvonen method does
The Karvonen method calculates training heart-rate targets from heart-rate reserve, not just maximum heart rate. That makes it more personalized because two athletes with the same age can have different resting heart rates and therefore different training targets.
Formula
Cleveland Clinic explains heart-rate reserve and notes that the Karvonen method is another name for using this reserve-based formula. Its heart-rate reserve guide is a useful non-competitor reference for the calculation concept.
Why this calculator includes max-HR options
Max heart rate is often estimated from age, but estimates can be wrong for individuals. This calculator includes the classic 220 − age method, the 208 − 0.7 × age method, and a manual max-HR option for athletes who have tested their own value.
How to use zones
Use these zones to guide aerobic base work, tempo sessions, threshold work, and hard intervals. Heart rate can lag behind effort, especially in intervals, heat, or fatigue, so combine it with pace, power, RPE, and breathing when needed.
Frequently asked questions
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It can be more individualized because resting heart rate is included. That makes a big difference for athletes with very low or very high resting heart rates.
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Use a tested max HR if you have one. Otherwise, age-predicted formulas are estimates. The calculator shows options so you can choose the assumption that fits your context.
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Yes. Some medications, especially beta blockers and other cardiovascular drugs, can change heart-rate response. In that case, professional guidance is better than calculator-only planning.
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Yes. Resting heart rate can change with fitness, fatigue, sleep, illness, and stress. Update it periodically for better zone estimates.
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Yes. It can be used for many endurance sports, but sport-specific heart-rate response may differ slightly.