Target Heart Rate Calculator
Find your training heart-rate zones by age and resting rate.
Estimated max heart rate
185 bpm
Zone 2 — easy (60–70%)
137–149 bpm
Zone 3 — steady (70–80%)
149–161 bpm
Zone 4 — hard (80–90%)
161–173 bpm
Zone 5 — max (90–100%)
173–185 bpm
Zones use the Karvonen method (heart-rate reserve), which anchors on your resting rate.
Why train by zone
Heart-rate zones proxy effort: zone 2 builds the aerobic engine and should dominate training volume; zones 4–5 sharpen speed but need recovery. The Karvonen method used here scales zones between your resting and max rate, personalizing them beyond the plain 220 − age formula.
Know the formula's limits
220 − age has a standard deviation of ±10–12 bpm — plenty of healthy 40-year-olds max at 195 or 165. If a field test (or a race finish sprint) shows a different max, trust the measurement over the formula.
Frequently asked questions
- How does the Target Heart Rate Calculator work?
- Find your training heart-rate zones by age and resting rate.
- Is the Target Heart Rate Calculator free to use?
- Yes. The Target Heart Rate Calculator is completely free, runs entirely in your browser, and requires no account or sign-up. Your inputs never leave your device.
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