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Fitness

Max Heart Rate Zones Calculator

Estimate your max heart rate and 5 training zones using Tanaka, Fox, or Gulati formulas with Karvonen heart rate reserve or simple percent-of-max.

Your details

Estimated max heart rate

184 bpm

Resting HR
60 bpm
Heart rate reserve
124 bpm

Zone 1 Recovery

122 to 134 bpm

50 to 60% intensity. Active recovery, warm-ups, easy walks.

Zone 2 Aerobic

134 to 146 bpm

60 to 70%. Base building, fat oxidation, the long easy run zone.

Zone 3 Tempo

146 to 159 bpm

70 to 80%. Aerobic capacity work. Comfortably hard.

Zone 4 Threshold

159 to 171 bpm

80 to 90%. Lactate threshold intervals. Hard sustained effort.

Zone 5 VO2 max

171 to 184 bpm

90 to 100%. Short maximal intervals. Top-end aerobic power.

Method

Karvonen heart rate reserve (HRR) method: target = (MaxHR - 60) x intensity + 60. Resting HR is folded into every zone, which makes the targets sensitive to your fitness level.

Formula

Using Tanaka (208 - 0.7 x age). This matches the typical recommendation for the selected profile.

Talk test

Talk test by zone. Z1 Recovery: hold a full conversation easily. Z2 Aerobic: short sentences between breaths. Z3 Tempo: three to five words at a time. Z4 Threshold: gasping single words. Z5 VO2 max: cannot speak.

Weekly mix

Aim for about 4 base sessions per week in Z1 to Z2 plus 1 to 2 high-intensity sessions in Z4 or Z5. Roughly the 80 to 20 polarized split (80% easy, 20% hard) backed by Seiler and used by most endurance coaches.

Frequently Asked Questions about the Max Heart Rate Zones Calculator

Tanaka (208 - 0.7 x age) vs Fox (220 - age): which is more accurate?
Tanaka. The 220 - age formula from Haskell and Fox (1971) was built from a small sample and never validated as a precise predictor; its standard error sits around 10 to 12 bpm and it systematically overestimates max HR for adults under 40 and underestimates it after about age 50. Tanaka et al. (2001) re-analyzed 351 published studies covering 18,712 subjects and produced 208 - 0.7 x age, which fits the data better across the adult range. The Tanaka standard deviation is also roughly +/-10 bpm, so neither formula replaces a graded exercise test, but Tanaka is the better default for the general population.
Why is the Karvonen heart rate reserve method better than simple percent of max?
Karvonen folds your resting HR into the math, so it adapts to your fitness. Heart rate reserve (HRR) is MaxHR minus RestHR; the target becomes HRR x intensity + RestHR. A trained athlete with a resting HR of 45 and an untrained adult with a resting HR of 75 share the same max HR at age 35, but Karvonen pushes the trained athlete's Zone 2 ceiling up because their HRR is wider. Simple percent-of-max ignores this and gives both athletes the same bpm target, which tends to underestimate intensity for unfit adults and overestimate it for fit ones.
Where do the 5 heart rate zones come from?
The 5-zone model is the consensus framework used by coaches, Garmin, Polar, Wahoo, and Zwift today. Joe Friel popularized the running version in The Triathlete's Training Bible (1998) and Andy Coggan published the cycling counterpart in his Functional Threshold Power framework. Both anchor the zones to physiological transitions: Zone 1 is recovery, Zone 2 sits below the first ventilatory threshold (aerobic base), Zone 3 is steady tempo, Zone 4 brackets lactate threshold, and Zone 5 covers VO2 max work. The exact percent bands (50 to 60, 60 to 70, 70 to 80, 80 to 90, 90 to 100) are a clean approximation of those transitions for most adults.
What is 80/20 polarized training and how does it map to zones?
Polarized training, made famous by sport scientist Stephen Seiler, observes that elite endurance athletes spend roughly 80% of their training time in Zone 1 to Zone 2 and roughly 20% in Zone 4 to Zone 5, with very little in Zone 3. The logic is that easy aerobic volume builds the mitochondrial base without much fatigue cost, while a small dose of true high-intensity work drives top-end gains. For most recreational athletes that translates to 3 to 4 easy aerobic sessions plus 1 to 2 hard interval sessions per week. Spending too much time in Zone 3 piles on fatigue without delivering the adaptations of either pole.
How does a lab VO2 max test compare to a formula-estimated max HR?
A graded exercise test on a treadmill or bike, with the athlete pushed to volitional exhaustion, gives an actual measured max HR. Tanaka and the other formulas have a standard deviation of about +/-10 bpm against measured values, which means roughly 1 in 3 people end up more than 10 bpm off from their formula prediction, and 1 in 20 are off by more than 20 bpm. If your perceived effort never matches the bpm targets the calculator produces, that is a strong signal to get a lab test, a field test like a 20-minute time trial, or to track HR during all-out interval sets and use the highest sustained value you can hit as your true max HR.

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