Target Heart Rate Calculator
Find your target heart-rate training zone from age and resting heart rate with the Karvonen method.
How it works
target HR = (max HR − resting HR) × intensity% + resting HR
The Karvonen method builds zones from your heart-rate reserve — the gap between your maximum and your resting heart rate — which personalizes them far better than a flat percentage of max. Pick a low and high intensity and it returns the beats-per-minute band to train in. Max heart rate here uses the common 220 − age estimate, so treat the edges as approximate.
Worked example
Age 35, resting 70 bpm, 50–85% intensity: max ≈ 185 and reserve = 185 − 70 = 115. Lower = 115 × 0.50 + 70 ≈ 128 bpm; upper = 115 × 0.85 + 70 ≈ 168 bpm.
Frequently asked questions
Why include resting heart rate?
Anchoring to your reserve makes the zone personal — a fit person with a low resting rate gets a different, more accurate band than a plain percent-of-max would give.
What intensity should I use?
General fitness lives around 50–70%; harder tempo and interval work runs 70–85%. Beginners start at the low end and build up as it feels easier.
How do I find my resting heart rate?
Measure right after waking, before getting up, for a full minute — or read the overnight low from a fitness tracker. The 70 bpm default is only a stand-in.
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General educational estimate, not medical advice. Talk to a doctor for anything about your health.