Zone 2 heart rate by age
A starting chart — and the reasons your own number may sit a little either side of it.
Zone 2 is the easy, conversational effort that builds your aerobic base. In heart-rate terms it's roughly 60–70% of your maximum heart rate. Since maximum heart rate falls with age, so does Zone 2. The chart below estimates both, using the Tanaka formula (208 − 0.7 × age), which is more accurate than the old 220 − age.
| Age | Est. max heart rate | Zone 2 (60–70%) |
|---|---|---|
| 20 | 194 | 116–136 bpm |
| 25 | 191 | 114–133 bpm |
| 30 | 187 | 112–131 bpm |
| 35 | 184 | 110–128 bpm |
| 40 | 180 | 108–126 bpm |
| 45 | 177 | 106–124 bpm |
| 50 | 173 | 104–121 bpm |
| 55 | 170 | 102–119 bpm |
| 60 | 166 | 100–116 bpm |
| 65 | 163 | 98–114 bpm |
| 70 | 159 | 95–111 bpm |
A guide, not gospel. Read on for why your real Zone 2 can differ — sometimes by 10 beats or more.
Three reasons your number may differ
- Your real maximum isn't the formula's. Any age-based estimate scatters by roughly 10 beats in each direction. If you've seen your true max in an all-out effort, use it — the whole chart shifts with it.
- Percentage of maximum vs. heart-rate reserve. This chart uses % of maximum. The Karvonen method uses your reserve (max minus resting heart rate) and gives different numbers at the same percentage — usually a little higher if you're fit. Here's how the two differ.
- Day-to-day life. Heat, caffeine, stress, poor sleep and dehydration all nudge heart rate up for the same effort. Some days Zone 2 will feel like it sits a few beats higher than usual. That's normal.
The simplest sanity check
If you can hold a full, unhurried conversation, you're in Zone 2. If your sentences start breaking up, you've drifted above it — trust that over any chart. Heart rate is the precise version of the same signal.
In The Zone does this for you. It estimates your zones with the Tanaka formula, lets you enter a measured maximum, and switches between percentage-of-maximum and the Karvonen method — then your watch taps you the moment you leave Zone 2, so you don't have to memorise a range. See what it does →
In The Zone is a training aid, not a medical device. Heart-rate zones are estimates. If something feels wrong while exercising, stop and speak to a doctor.