Your maximum heart rate is the highest your heart reaches at all-out effort. Formulas estimate it from age, but they disagree: for a 40-year-old they give anywhere from about 178 to 185 bpm. Individual variation reaches ±15–20 bpm, so WIMSTA shows a range across nine formulas rather than one number — and your true max can only be found with a maximal exercise test.
Why "220 minus age" is inaccurate
The famous 220 − age was never derived from careful research — it has a standard deviation of ±10–12 bpm and drifts for older and younger adults. Tanaka (208 − 0.7·age) fits the population better, and Gulati (206 − 0.88·age) is validated specifically in women. We show all nine so you see the real spread.
Which zone system?
- % of max HR — simplest, needs only your max. The Polar default.
- Karvonen (reserve) — uses max minus resting HR; more accurate at the edges. The Garmin default when you enter resting HR.
- Friel (threshold) — anchored to your lactate-threshold HR; the most physiological, needs a test.
All three use exactly five zones so the tables stay comparable.
FAQ
Is 220 minus age accurate?
No — it is the best-known formula but the least accurate individually, with a standard deviation of about ±10–12 bpm. Use it as one estimate among several, which is why we show nine.
What is a good maximum heart rate for age?
It falls with age — roughly 190 bpm at 25, 180 at 40, 166 at 60 by the Tanaka formula. But individual values sit up to ±15–20 bpm from any formula, so treat the number as a range, not a target.
Is your max heart rate higher if you are fitter?
No — fitness barely changes your maximum heart rate; that is a common myth. Training lowers your RESTING heart rate instead, which is exactly why the Karvonen (reserve) method is more accurate for fitter people.
Why do Garmin and Polar show different zones?
They use different default models. %HRmax takes percentages of your max; Karvonen uses your heart-rate reserve. On the same person the top of Zone 2 can differ by ~11 bpm — neither is wrong, they anchor differently.
What is the best heart rate for burning fat?
The "fat-burning zone" is misleading in popular use. Lower intensity burns a higher fraction of fat but fewer total calories; higher intensity burns more calories overall. For fat loss, total energy matters more than the zone.
Population estimates for general fitness, not a medical assessment. With heart conditions, beta-blockers (which lower your max heart rate) or symptoms during exercise, your target zones should be set by a doctor.
Tanaka, Monahan & Seals (2001), JACC 37(1):153–6. · Gulati et al. (2010), Circulation 122:130–137. · Karvonen, Kentala & Mustala (1957), Ann Med Exp Biol Fenn 35(3):307–15. · Nes et al. (2013), HUNT Fitness Study, Scand J Med Sci Sports 23(6):697–704. · Friel, The Cyclist's Training Bible (LTHR zones). · ACSM Guidelines for Exercise Testing (%HRR).