Heart Rate Zones Calculator — educational

Estimate your training heart-rate zones from your age and resting heart rate. Two methods — the simpler percent-HRmax and the tighter Karvonen heart-rate reserve — and the five standard zones (Recovery through VO2 Max). All math runs in your browser. Nothing is uploaded.

Measure first thing in the morning, before getting up.
Method
Estimated HRmax
—
bpm

Your zones

#
Zone
% range
BPM
What it does
How this calculator works
  • HRmax. Estimated with the Tanaka 2001 formula: HRmax = 208 − 0.7 × age (replaces the older 220 − age rule, which overestimates HRmax in older adults).
  • Percent-HRmax method. The simple band: target bpm = HRmax × percent. Easier to explain, doesn't need a resting HR.
  • Karvonen method. Uses heart rate reserve (HRR = HRmax − resting HR). The band is target = HRR × pct + resting HR, which is tighter at the low zones and reflects that someone with a 50 bpm resting HR trains differently from someone with a 70 bpm resting HR.
  • Zones. The five 10-percent bands (50–60, 60–70, 70–80, 80–90, 90–100) are a training taxonomy, not a medical prescription. They're widely used by endurance coaches but the exact percentages vary by source.
  • HRmax is a population heuristic. The Tanaka formula has a standard deviation of roughly ±10 bpm. If you have a measured HRmax from a lab test, prefer that over the formula. The bpm bands here are rounded to integers.
  • Karvonen needs resting HR < HRmax. We validate that here. If your resting HR is unusually high (or your HRmax is unusually low), the Karvonen method may be undefined.
  • Educational only. These numbers describe training intensity, not cardiovascular health. Talk to a doctor before starting or changing an exercise programme.
  • Nothing is uploaded. The whole thing runs in your browser.