Max heart rate
179bpm
Tanaka
220 − age
178bpm
classic
Zone 2
107–125bpm
aerobic base
Vigorous from
138bpm
about 77% of max
Show the math
Max HR = 208 − 0.7 × 42 = 179 bpm
Heart rate zones at 42
| Zone | BPM | % of max | Feels like |
|---|---|---|---|
| Zone 1 · Recovery | 89–107 | 50–60% | Easy, conversational |
| Zone 2 · Aerobic base | 107–125 | 60–70% | Steady, can still talk |
| Zone 3 · Tempo | 125–143 | 70–80% | Comfortably hard |
| Zone 4 · Threshold | 143–161 | 80–90% | Hard, short phrases |
| Zone 5 · Max effort | 161–179 | 90–100% | All-out, seconds to minutes |
Karvonen zones by resting heart rate
| Resting HR | Zone 1 | Zone 2 | Zone 3 | Zone 4 |
|---|---|---|---|---|
| Resting 55 | 117–129 | 129–142 | 142–154 | 154–166 |
| Resting 65 | 122–133 | 133–145 | 145–156 | 156–167 |
| Resting 75 | 127–137 | 137–148 | 148–158 | 158–168 |
Karvonen: resting + (max − resting) × intensity. More personal if you know your resting rate.
How to use it
- Enter your numbers. Switch between US and metric units at any time.
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These are estimates, not a diagnosis. A clinician can account for your health history and medicines.
Other ages
Common questions
What is a good heart rate zone for a 42-year-old?
Zone 2, about 107 to 125 bpm, builds aerobic base. Moderate exercise sits around 114 to 136 bpm.
What is the max heart rate at 42?
About 179 bpm by the Tanaka formula, or 178 by 220 minus age. Individual max can differ by 10 or more beats.