Heart Rate Zone Calculator
Maximum heart rate and the five training zones.
Last updated
Your details
Optional — enables the more accurate Karvonen method.
Result
- Maximum heart rate
- 187 bpm
- Zone 1 — Recovery
- 124 – 136 bpm
- Zone 2 — Endurance
- 136 – 149 bpm
- Zone 3 — Aerobic
- 149 – 162 bpm
- Zone 4 — Threshold
- 162 – 174 bpm
- Zone 5 — Maximum
- 174 – 187 bpm
- Heart rate reserve
- 127 bpm
Tanaka formula: 208 − 0.7 × 30
Warm-up, cool-down, active recovery
Conversational pace; builds aerobic base
Moderate effort, improves efficiency
Hard; raises lactate threshold
Short intervals only
Why 208 − 0.7 × age, not 220 − age
The familiar "220 minus age" was never derived from research; it appeared in a 1970s summary and stuck. Tanaka's 2001 meta-analysis of 351 studies produced 208 − 0.7 × age, which fits measured data considerably better, especially for people over 40.
Even so, individual maximum heart rates vary by around ±10 bpm from any formula. A properly conducted maximal effort test gives your real number.
The Karvonen method
Entering a resting heart rate switches the zones to the Karvonen formula, which works from heart rate reserve — the gap between resting and maximum — rather than from maximum alone.
This matters because a fit person with a resting rate of 45 and an unfit person at 75 should not train at the same absolute heart rate for the same relative effort. Measure your resting rate immediately on waking, before getting up.
Formula & methodology
What this calculator assumes
- Individual maximum heart rate varies by roughly ±10 bpm from any age-based formula; only a maximal effort test gives your real figure.
- The familiar "220 − age" was never derived from research and fits measured data poorly, particularly over the age of 40.
Sources
- Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. Journal of the American College of Cardiology, 2001;37(1):153–156.
- Karvonen MJ, Kentala E, Mustala O. The effects of training on heart rate. Annales Medicinae Experimentalis et Biologiae Fenniae, 1957;35(3):307–315.
Frequently asked questions
Why is zone 2 so popular?
It builds mitochondrial density and fat oxidation with low recovery cost, so large volumes can be sustained week after week. Most endurance athletes spend the majority of their training there.
Is 220 minus age accurate for me?
It is a population average with a standard deviation of about twelve beats per minute, so for any individual it can be well out. If you have a measured maximum from a field test or a lab, enter that instead — the zones derived from it are far more useful than zones derived from your birthday.
What if my watch reports a different zone?
Most devices use the same percentage-of-maximum model but some use heart rate reserve, which subtracts your resting rate before taking percentages and shifts the boundaries upward. Neither is wrong; they are different definitions, so compare within one system rather than across two.
How much time should I spend in each zone?
The pattern most endurance programmes converge on is roughly 80% of training time in zones 1 and 2 and 20% in zones 4 and 5, with relatively little in zone 3. The easy work builds the aerobic base; the hard work provides the stimulus; the middle is tiring without being especially productive.