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Performance & Training

Target Heart Rate Calculator

Find your max heart rate and personalized training zones.

Formula: Tanaka + Karvonen (HRR)Reviewed for accuracy on Sun, Aug 2, 2026
yrs
bpm

Measure first thing in the morning. Default 70 bpm.

Enter your details to see your result.

Key takeaways

  • This uses Tanaka's 208 − 0.7 × age, not the old 220 − age. The 220 formula has no published derivation and misestimates at both ends of the age range.1
  • Zones are calculated from heart rate reserve (Karvonen), which accounts for your resting rate and is more accurate than a plain percentage of max.2
  • Any age formula carries a standard deviation of roughly ±10–12 bpm. Two people the same age can have genuinely different maximums.1
  • Most of your training should be easy — zone 2 or below. The common mistake is spending every session in the middle.
  • Aim for 150 minutes of moderate or 75 of vigorous activity a week as the baseline.5

Understanding your result

Your max heart rate sets the ceiling for training zones. The Tanaka formula (208 − 0.7×age) is more accurate than the older 220 − age.

The Karvonen method uses your heart rate reserve (max − resting) to personalize each zone's bpm range.

Why not 220 minus your age

The 220 − age formula is the most widely repeated number in fitness and it has no real pedigree. It was not derived from a study; it appears to have emerged from a rough line drawn through a scatter of data in the 1970s and then propagated by repetition.

Tanaka, Monahan and Seals revisited the question properly in 2001, with a meta-analysis of 351 studies covering nearly 19,000 subjects plus a prospective validation in 514 more. Their regression gave 208 − 0.7 × age, and they showed the classic formula underestimates maximum heart rate in older adults and overestimates it in the young.1

  • Age 204 bpm difference (Tanaka − 220-age)

    Tanaka 194, classic 200 — classic reads high

  • Age 400 bpm difference (Tanaka − 220-age)

    Both 180 — they cross here

  • Age 606 bpm difference (Tanaka − 220-age)

    Tanaka 166, classic 160 — classic reads low

  • Age 7510 bpm difference (Tanaka − 220-age)

    Tanaka 156, classic 145

Where the two formulas disagree. Predicted maximum heart rate. The gap widens with age, and it is the older end where the old formula does the most harm.
Where the two formulas disagree
MethodValue (bpm difference (Tanaka − 220-age))
Age 204
Age 400
Age 606
Age 7510

Every age formula is a population average

Tanaka's own paper reports a standard deviation around 10 bpm, meaning roughly a third of people are more than 10 beats from their predicted max. If your training feels wildly out of step with the zones, trust the effort and not the arithmetic — or get a proper test.

Heart rate reserve, and why it is better

There are two ways to build zones. The simple one takes percentages of maximum heart rate. The better one, published by Karvonen in 1957, works from heart rate reserve — the span between your resting and maximum rates.2

The difference matters because resting heart rate varies enormously between people. A well-trained endurance athlete might rest at 45 bpm and an untrained person at 75. At 70% of max they are doing very different amounts of work; at 70% of heart rate reserve they are much closer to comparable. ACSM recommends the reserve method for exercise prescription for this reason.3

Training zones as a percentage of heart rate reserve.
Zone% of reserveWhat it does
1 — Recovery (success)50–60%Active recovery, warm-up. Conversational, feels almost too easy.
2 — Aerobic base (success)60–70%Builds mitochondria and fat oxidation. Where most training should live.
3 — Tempo (warning)70–80%Sustainable hard effort. Useful, and the zone people overuse.
4 — Threshold (warning)80–90%At or near lactate threshold. Raises the pace you can hold.
5 — VO₂ max (danger)90–100%Intervals of minutes at most. High return, high cost.

The mistake almost everyone makes

It has a name among coaches: the grey zone. Easy sessions get run slightly too hard because they feel unproductive, and hard sessions get run slightly too easy because the legs are tired from the last one. Everything converges on zone 3 — moderately hard, all the time.

The result is training that generates real fatigue without a strong adaptive signal in either direction. The alternative most endurance coaching converges on is polarised: the large majority of volume genuinely easy, a small minority genuinely hard, and comparatively little in the middle.

  • Easy means easy. Zone 2 should allow full sentences. If you cannot hold a conversation, you are not in zone 2, whatever the watch says.
  • Hard means hard. A weekly interval session in zones 4–5 is where high-intensity work earns its keep — Weston's meta-analysis found HIIT produced substantially greater VO₂ max improvement than moderate continuous training in cardiometabolic patients.4
  • Volume beats intensity for the base. The aerobic adaptations that make you durable come mostly from time spent at low intensity.
  • Two hard sessions a week is plenty for most people who are not competing.

What can throw the numbers off

  • Beta blockers and some other medications lower both resting and maximum heart rate substantially. Heart-rate zones are not usable in the normal way — ask your doctor and use perceived effort instead.
  • Heat and dehydration raise heart rate at a given pace, sometimes by 10–15 bpm. This is cardiac drift, not a fitness change.
  • Caffeine, illness, poor sleep and stress all shift resting and working heart rate.
  • Wrist optical sensors are unreliable during intervals and weights — they lag, and they sometimes lock onto cadence instead of pulse. A chest strap is far better if the numbers matter to you.
  • Altitude raises heart rate at any given pace until you acclimatise.

Get checked before starting hard training

If you have a cardiac condition, chest pain on exertion, uncontrolled blood pressure, or have been sedentary for years, speak to a doctor before beginning high-intensity work. This calculator estimates training zones for healthy adults; it cannot tell you whether intense exercise is safe for you.

Terms used on this page

Heart rate reserve (HRR)
Maximum heart rate minus resting heart rate — the span you actually train within. Zones built from it adapt to your fitness in a way percentages of max do not.
Karvonen method
Calculating a target rate as resting + (percentage × heart rate reserve). Published in 1957 and still the method ACSM recommends.
Lactate threshold
The intensity above which lactate accumulates faster than it is cleared. Roughly the hardest effort you can hold for about an hour, and a better predictor of endurance performance than VO₂ max.
Cardiac drift
Heart rate creeping upward at constant pace as a session goes on, driven by heat and fluid loss rather than by increased effort.

The formula

Max HR (Tanaka)
MaxHR = 208 − 0.7 × age
Karvonen zone
Target HR = (MaxHR − RestingHR) × intensity% + RestingHR
Worked example
  1. Age 30, resting 70 bpm
  2. MaxHR = 208 − 21 = 187
  3. Zone 3 (70–80%): (187−70)×0.70+70 = 151.9 to (187−70)×0.80+70 = 163.6
Result: Cardio zone ≈ 152–164 bpm

Source: Tanaka + Karvonen (HRR). Published clinical/scientific formula.

Limitations

  • Max-HR formulas are estimates; individual max can vary by ±10 bpm.
  • Some medications (e.g. beta blockers) lower heart rate and invalidate zone targets.

References

Not medical advice. This calculator is for general informational purposes only and is not a substitute for professional medical guidance. Always consult a qualified healthcare provider before making decisions about your health. Read the full medical disclaimer.

Reviewed for accuracy on Sun, Aug 2, 2026