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Heart Rate Zones Calculator

Your estimated maximum heart rate is 220 minus your age — 188 bpm at age 32 — and training zones are carved out of the gap between resting and maximum heart rate, the Karvonen or heart-rate-reserve method. Enter age and resting heart rate to get zone boundaries in actual beats per minute rather than abstract percentages.

Max heart rate
188
bpm
Your estimated max heart rate is 188 bpm
From the 220 − age population estimate; your true max can sit 10–12 bpm either side, and Karvonen sets each zone off your resting HR.
Training zones
Rest 62 bpm → Max 188 bpm
Z1 · Recovery
125–138
Z2 · Endurance
138–150
Z3 · Tempo
150–163
Z4 · Threshold
163–175
Z5 · VO₂ max
175–188
Karvonen method: zone% × heart-rate reserve + rest HR.
Inputs
Age , resting heart rate bpm
220 − age is only an anchor
It estimates a population average — your true max can sit 10–12 bpm either side of 188. A field or lab test pins it down; Karvonen then personalizes each zone using your resting HR.
Train mostly easy (80/20)
Endurance athletes keep roughly 80% of training in the easy Zone 1–2 range and only 20% hard. A chest strap reads zones more reliably than a wrist optical sensor.
Ask a follow-up
Uses your inputs above
188 max heart rate. Want to try a variation?

The math

Reviewed 2026
Formula
HRmax = 220 − age; zone = rest + (HRmax − rest) · %

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Example: how heart rate zones is calculated

Step-by-step with default inputs

Suppose you put the default values into Heart Rate Zones Calculator:

Age
32 years
Resting heart rate
62 bpm

Plug those into the formula HRmax = 220 − age; zone = rest + (HRmax − rest) · % and the result is:

Max heart rate
188

How to calculate heart rate zones by hand

  1. Subtract your age from 220 to estimate maximum heart rate (HRmax).
  2. Subtract your resting heart rate (rest) from HRmax to get heart-rate reserve.
  3. Multiply the reserve by the zone's intensity percentage.
  4. Add the resting heart rate back — that is the zone boundary in bpm.

How does the heart rate zones calculator work?

Maximum heart rate is estimated with the widely used 220 - age rule of thumb — a convenient population average this calculator adopts, not a figure drawn from its cited source. Each zone boundary then comes from the Karvonen method (the cited reference): target = resting HR + (max HR - resting HR) x intensity percentage. Working from heart-rate reserve rather than raw percentages of maximum personalizes the zones — a lower resting heart rate widens the reserve, shifting every zone. Because 220 - age is only an average and individual maximums at the same age differ meaningfully, a maximum observed in genuinely hard efforts or a lab test produces better zones than the rule of thumb.

References: Karvonen method.

Last reviewed July 2, 2026 · Editorial policy

Frequently asked questions

What is the Karvonen formula?

Target heart rate = resting HR + (maximum HR - resting HR) x intensity. It anchors training zones to your heart-rate reserve instead of raw percentages of maximum, so two people of the same age with different resting rates get different, more personal zones.

Why does resting heart rate matter for zones?

Because zones are computed from the reserve between resting and maximum. At the defaults — age 32, resting 62 bpm — a 70% intensity lands at 62 + (188 - 62) x 0.7, about 150 bpm; a fitter person with a 50 bpm resting rate would get a different boundary from the same formula.

How accurate is 220 minus age?

It is a population-level estimate, good enough for setting rough training zones but not a personal measurement — real maximums at any age spread widely around it. If you have recorded a higher heart rate in an all-out effort, use that number instead.

How accurate is this heart rate zones calculator?

The math is deterministic — the same inputs always produce the same output, and the formula is shown above. Accuracy of the answer for your situation depends on how well your inputs match reality and how well the formula models the question.

Is this a substitute for medical advice?

No. Health calculators give informational baselines from published formulas. For decisions about your body, talk to a clinician.

How do I share my result?

Hit Share at the top of the page. Every input you change is encoded in the URL, so a permalink reproduces exactly what you see. No account needed.

Guides

What heart rate should I exercise at?Your target heart rate for exercise: 50–70% of max for moderate effort, 70–85% for vigorous, with max estimated as about 220 minus your age.