Max heart rate
181bpm
Tanaka
220 − age
182bpm
classic
Zone 2
109–127bpm
aerobic base
Vigorous from
140bpm
about 77% of max
Show the math
Max HR = 208 − 0.7 × 38 = 181 bpm
Heart rate zones at 38
| Zone | BPM | % of max | Feels like |
|---|---|---|---|
| Zone 1 · Recovery | 91–109 | 50–60% | Easy, conversational |
| Zone 2 · Aerobic base | 109–127 | 60–70% | Steady, can still talk |
| Zone 3 · Tempo | 127–145 | 70–80% | Comfortably hard |
| Zone 4 · Threshold | 145–163 | 80–90% | Hard, short phrases |
| Zone 5 · Max effort | 163–181 | 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 | 118–131 | 131–143 | 143–156 | 156–169 |
| Resting 65 | 123–135 | 135–146 | 146–158 | 158–170 |
| Resting 75 | 128–139 | 139–149 | 149–160 | 160–171 |
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.
- Results update as you type, and the formula is shown so you can check it.
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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 38-year-old?
Zone 2, about 109 to 127 bpm, builds aerobic base. Moderate exercise sits around 116 to 138 bpm.
What is the max heart rate at 38?
About 181 bpm by the Tanaka formula, or 182 by 220 minus age. Individual max can differ by 10 or more beats.