Heart Rate Zone Calculator
Five training zones from your max and resting heart rate.
Enter your values
Results update instantly as you type — no submit needed.
Results
- Estimated max heart rate
- 184 bpm
- Heart rate reserve
- 124 bpm
- Zone 2 (fat-burning base)
- 134 – 146 bpm
| Zone | Range | Purpose |
|---|---|---|
| Zone 1 — recovery | 122 – 134 bpm | recovery |
| Zone 2 — endurance | 134 – 146 bpm | endurance |
| Zone 3 — tempo | 146 – 159 bpm | tempo |
| Zone 4 — threshold | 159 – 171 bpm | threshold |
| Zone 5 — VO2 max | 171 – 184 bpm | VO2 max |
Quick answer
Karvonen zones use heart rate reserve: target = resting + intensity × (max − resting), which is more accurate than percentage of max alone.
Target HR = HRrest + %·(HRmax − HRrest)
How to use the Heart Rate Zone Calculator
- 1Enter your age and resting heart rate.
- 2Add a lab-tested max HR if you have one.
- 3Train inside the zone that matches your session.
Frequently asked questions
Why 208 − 0.7×age?
The Tanaka formula predicts max heart rate more accurately across ages than the older 220 − age rule.
How do I find resting HR?
Measure first thing in the morning before getting up, over three consecutive days, and take the average.