Estimates training heart-rate zones using your age (for maximum heart rate) and, if you enter it, resting heart rate for the Karvonen (heart-rate reserve) method. These are fitness-planning bands, not medical targets—medications, fatigue, heat, and fitness level change how hard the same pace feels.
Max HR estimate: HRmax ≈ 220 − age (many alternatives exist). Five bands use 50–60%, 60–70%, 70–80%, 80–90%, and 90–100% of either reserve (Karvonen) or of max HR when resting HR is absent.
Beta blockers, illness, heat, and fitness shift HR response—zones are planning aids, not prescriptions.
This heart rate zone estimator applies the formulas described on this page to the values you enter. Outputs are not financial, tax, legal, or medical advice.
Last reviewed: 2026-04-17
It is only a population estimate; measured max varies widely. Use zones as flexible guides—rating of perceived exertion and talk tests still matter.
With resting HR, the tool can apply the Karvonen (heart-rate reserve) approach. Without it, zones fall back to percentages of the estimated max HR only.
Some drugs blunt exercise heart rate. Ask your clinician how to interpret zones or whether another intensity prescription fits better.