Heart Rate Zone Calculator
Five training zones in beats per minute from your age, resting heart rate or measured max.
With the Karvonen method, target HR = resting HR + intensity × (max HR − resting HR). For a 40-year-old with a resting HR of 60, max HR is 208 − 0.7 × 40 = 180, so Zone 2 (60–70%) is 132–144 bpm.
Free, runs in your browser. Nothing you enter is uploaded.
How to use it
- Enter age and resting heart rate (measure it on waking).
- Choose a max heart rate formula, or enter your measured max.
- Choose Karvonen or % of max and read your zones.
What you enter
- Age
- Resting heart rate
- Max HR formula
- Zone method
What you get
- Max heart rate
- Heart rate reserve
- Zones 1–5 in bpm
Formula
Max HR = 208 − 0.7 × age (Tanaka) | Target = HRrest + intensity × (HRmax − HRrest) (Karvonen)
Worked example
Input: Age 40, resting HR 60, Tanaka, Karvonen
Result: Max 180 bpm; Zone 2 132–144 bpm; Zone 4 156–168 bpm
Most weekly training would sit in Zone 2, with short Zone 4 sessions.
Questions
What is zone 2 heart rate?
60–70% of heart rate reserve or max heart rate: an easy pace where you can still talk in full sentences. It builds aerobic base and fat oxidation.
Is 220 minus age accurate?
It can be off by 10–12 bpm either way. Tanaka's 208 − 0.7 × age fits adults better, especially over 40. A supervised max test is most accurate.
What is the Karvonen formula?
It uses heart rate reserve (max minus resting) so zones reflect your fitness: target = resting + % intensity × reserve.
What heart rate is too high during exercise?
Sustained rates above your estimated max, or any chest pain, dizziness or unusual breathlessness, mean stop and seek medical advice.
Limitations
- Beta blockers and some heart conditions change heart rate response; ask your clinician.
References
- Tanaka H, Monahan KD, Seals DR (2001) Journal of the American College of Cardiology 37(1):153-156.
- American College of Sports Medicine (2021).
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