Heart Rate Zone Calculator
Training zones 1–5 by % of max heart rate and by the Karvonen (heart-rate reserve) method.
Free to use · No account required
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How it works
Max HR ≈ 220 − age (or Tanaka: 208 − 0.7 × age). Karvonen target = ((HRmax − HRrest) × intensity %) + HRrest.