Heart Rate Zone Calculator
Find your training zones using the Karvonen heart rate reserve method.
The 220 − age formula is a population estimate with meaningful individual variation. Not medical advice — consult a doctor before starting a new training program, especially with any heart condition.
Estimated max heart rate
190 bpm
Heart rate reserve
125 bpm
Max minus resting
Zone overview
For informational and educational purposes only — not medical advice, and not a substitute for consulting a qualified professional about your specific situation. TrueMeasureKit is not liable for decisions made based on these results. See our Terms of Service.
Why the Karvonen method
The simplest heart rate zone method just takes a flat percentage of your estimated max heart rate. Karvonen instead uses heart rate reserve — the gap between your resting and max heart rate — which accounts for fitness level. Two people with the same max heart rate but very different resting heart rates (a sign of different cardiovascular fitness) get meaningfully different zone boundaries under Karvonen, which better reflects real effort.
Frequently asked questions
What's the Karvonen method?
A heart-rate-reserve formula that factors in your resting heart rate, not just age — it tends to be more personalized than simple age-based zone formulas, especially for people with unusually low or high resting heart rates.
Do I need a resting heart rate measurement for this to be accurate?
Yes — take it first thing in the morning before getting out of bed, over 60 seconds, for the most accurate reading. A rough guess will still produce reasonable zones, but a real measurement improves precision.