Calculate heart rate zones, including zone 2, from your age with the Tanaka or 220 − age maximum, or from resting heart rate with the Karvonen method.
Heart Rate Zones, Maximum Heart Rate, and Zone 2
Heart-rate zones divide an estimated or measured maximum into training-intensity bands. Calculation details compare Tanaka and traditional Fox estimates. Bands use the selected percent-of-maximum method or Karvonen reserve based on Tanaka. Age estimates are limited here to 18–81, the laboratory validation range of the Tanaka healthy adult study.
Formula and Method
Tanaka maximum HR = 208 – 0.7 x age. Fox maximum HR = 220 – age. Percent-of-max target = maximum HR x intensity fraction. Karvonen target = resting HR + intensity fraction x (maximum HR – resting HR).
Illustrative five-band convention used in the calculator. Labels are descriptive conventions, not measurements of personal physiological or safety thresholds.
| Reference | Range or value | Illustrative label; not a measured threshold |
|---|---|---|
| Zone 1 | 50-60% | Very easy |
| Zone 2 | 60-70% | Easy aerobic |
| Zone 3 | 70-80% | Moderate |
| Zone 4 | 80-90% | Hard |
| Zone 5 | 90-100% | Very hard |
How to Use the Result
Choose one method and compare its percentage basis consistently. Zone 2 is the primary result here, but percentages of maximum and reserve are different methods. Neither establishes a personal aerobic or lactate threshold. Definitions vary among coaches, devices and laboratories; compare their percentage basis before assuming the labels match.
Assumptions and Limitations
Maximum-heart-rate equations are estimates, and percentage boundaries are conventions rather than sharp physiological switches. Perceived exertion, talk-test response, pace or power, medication effects, and clinician guidance may be more useful than a formula for some people.
Sources
- Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited, 2001.
- Fox SM, Naughton JP, Haskell WL. Physical activity and the prevention of coronary heart disease, 1971.
