Heart Rate Zones
Training zones from a published estimate of maximum heart rate — with the spread that estimate carries.
Estimated maximum heart rate
180 bpm (± 10 bpm, one standard deviation)
- Zones
- Zone 1 — very light — 50–60 % — 90–108 bpm Zone 2 — light, endurance — 60–70 % — 108–126 bpm Zone 3 — moderate, tempo — 70–80 % — 126–144 bpm Zone 4 — hard, threshold — 80–90 % — 144–162 bpm Zone 5 — maximum — 90–100 % — 162–180 bpm
- The older estimate
- 180 bpm — "220 minus age", shown only for comparison
Where this comes from
- Rule
- Percentage of the estimated maximum
- Sources
-
- Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. Journal of the American College of Cardiology, 2001 — a meta-analysis of 351 studies and 18 712 subjects
- Karvonen MJ, Kentala E, Mustala O. The effects of training on heart rate. Annales Medicinae Experimentalis et Biologiae Fenniae, 1957
- Caveat
- An age-predicted maximum carries about 10 bpm of standard deviation: these are bands, not thresholds.
Five training zones, from an estimate of your maximum heart rate. The estimate comes from Tanaka, Monahan and Seals (2001) rather than from "220 minus age", and it is shown with the spread it genuinely carries — which is the number every other calculator leaves out.
How it works
The maximum is estimated as 208 − 0.7 × age. That equation comes from a meta-analysis of 351 studies covering 18 712 people, cross-validated on 514 more. It replaced "220 minus age", which has no traceable derivation and is systematically wrong at both ends of the age range — too high for the young, far too low for the old. Both are shown here so you can see the difference, and they happen to cross at about forty.
The standard deviation is around ten beats per minute, and that is the part worth reading twice. An estimate of 180 means two people in three of that age fall between 170 and 190, and one in twenty falls outside 160 to 200. A measured maximum from a proper test beats any formula, and where the zones actually matter, a test is what should be used.
The two ways of placing the zones are both named methods and they do not agree. Percentage of maximum is the simple one. Karvonen works from the reserve — the gap between your resting rate and your maximum — which pushes every boundary upward and tracks effort better for anyone whose resting rate is unusual. A zone quoted without saying which method produced it is ambiguous by ten beats or more.
The split at 50, 60, 70, 80 and 90 per cent is a widely used convention, not a finding. Different federations and coaches draw the boundaries differently, and none of them is the correct one.
Examples
| Case | Input | Result |
|---|---|---|
| At forty | age 40 | maximum 180 bpm — Tanaka and the old rule agree here |
| At twenty | age 20 | Tanaka 194, "220 − age" 200 |
| At seventy | age 70 | Tanaka 159, "220 − age" 150 |
| The method matters | age 40, resting 55, Karvonen | zone 2 is 130–143, not 108–126 |
Frequently asked questions
Why not "220 minus age"?
Because nobody has been able to trace where it came from, and it is wrong in a predictable direction: it overestimates the maximum for young people and underestimates it badly for older ones. At seventy the two formulas differ by nine beats. It is shown here only so the difference is visible.
How accurate is the estimate?
Within about ten beats per minute for two people in three, and outside that for the rest. That is not a flaw in this particular formula — maximum heart rate genuinely varies that much between people of the same age. It is why the figure is shown with its spread rather than as a clean number.
Which method should I use?
Karvonen, if you know your resting rate, and especially if it is unusually low or high — it accounts for where your range actually starts. Percentage of maximum is what most watches display by default, so use that one if you want the zones to match what your device shows.
Can I use this if I have a heart condition?
These are estimates from population averages and nothing here is medical advice. If a doctor has given you a target range, that range was set for you and this one was not.
Good to know
- Everything on this page is an estimate from published population data. It is not medical advice, and it does not know anything about you beyond the two numbers you typed.