Health & Medicine · Fitness · Cardio & Endurance
Maximum Heart Rate Calculator
Estimate your maximum heart rate (MHR) using age-based formulas and calculate personalized target heart rate training zones.
Calculator
Formula
MHR = maximum heart rate in beats per minute (bpm). Age = the individual's age in years. The Tanaka formula (208 − 0.7 × age) is preferred over the classic Fox formula (220 − age) for its greater accuracy across a broader population.
Source: Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. Journal of the American College of Cardiology. 2001;37(1):153-156.
How it works
Maximum heart rate (MHR) is the highest number of times your heart can beat per minute during maximal exertion. It declines predictably with age, making age the primary predictor. The Tanaka formula (MHR = 208 − 0.7 × age) was derived from a meta-analysis of 351 studies covering 18,712 subjects and is now the most widely recommended formula in sports science. The classic Fox formula (220 − age) remains popular but tends to overestimate MHR in older adults and underestimate it in younger adults.
Once MHR is known, training zones are calculated as percentages of it. When a resting heart rate (RHR) is provided, the Karvonen method uses heart rate reserve (HRR = MHR − RHR) to compute zones, which more accurately reflects individual cardiovascular fitness. Without RHR, straight percentage-of-MHR zones are used.
These zones guide workout intensity: Zone 1 promotes recovery, Zone 2 builds aerobic base and fat metabolism, Zone 3 improves aerobic capacity, Zone 4 raises lactate threshold, and Zone 5 trains peak power and speed.
Worked example
Example: 35-year-old runner, resting HR 60 bpm, using Tanaka formula
Step 1 — Maximum Heart Rate: MHR = 208 − (0.7 × 35) = 208 − 24.5 = 184 bpm
Step 2 — Heart Rate Reserve (HRR): HRR = 184 − 60 = 124 bpm
Step 3 — Karvonen Zone Boundaries:
Zone 1 (50–60%): 60 + (0.50 × 124) to 60 + (0.60 × 124) = 122–134 bpm
Zone 2 (60–70%): 134–147 bpm
Zone 3 (70–80%): 147–159 bpm
Zone 4 (80–90%): 159–172 bpm
Zone 5 (90–100%): 172–184 bpm
This runner should target 134–147 bpm for long easy runs and 159–172 bpm for tempo workouts.
Limitations & notes
All age-predicted MHR formulas carry a standard deviation of approximately ±10–12 bpm, meaning your true MHR could differ noticeably from the estimate. Genetics, fitness level, altitude, medications (especially beta-blockers), and heat all affect actual MHR. The only way to know your true MHR precisely is through a medically supervised maximal exercise test. Do not attempt to reach your estimated MHR without medical clearance if you are sedentary, over 40, or have any cardiovascular risk factors. The Tanaka formula was validated primarily on healthy adults; accuracy may be reduced in elite athletes or those with heart conditions.
Frequently asked questions
Which maximum heart rate formula is most accurate?
The Tanaka formula (208 − 0.7 × age) is currently recommended by most sports scientists based on a large meta-analysis. The classic Fox formula (220 − age) is well-known but less accurate, especially for people over 40. The Gellish and Nes formulas perform comparably to Tanaka. No age-based formula is perfectly accurate for every individual — expect ±10–12 bpm variation.
What is the Karvonen method and why is it better?
The Karvonen method calculates training zones based on heart rate reserve (HRR = MHR − resting HR) rather than MHR alone. This accounts for individual fitness levels: a trained athlete with a low resting HR of 45 bpm and an untrained person with a resting HR of 80 bpm have very different cardiovascular ranges even if they share the same MHR. Karvonen zones are therefore more personalised and are preferred by coaches for serious training prescription.
Is it dangerous to exercise at or near my maximum heart rate?
Briefly reaching or approaching MHR during high-intensity intervals is normal for healthy, trained individuals. However, sustained exercise near MHR is extremely demanding and appropriate only for short efforts. If you are new to exercise, have cardiovascular disease, or are over 45 without a recent medical evaluation, consult your doctor before performing high-intensity training. Do not attempt to find your true MHR without medical supervision if any risk factors apply.
Why does my heart rate monitor sometimes show numbers above my estimated MHR?
Because age-based estimates are averages, your true MHR may be higher than predicted. Some people naturally have a higher MHR, and trained athletes often exceed the formula estimate. Measurement errors (motion artifacts, poor sensor contact) can also cause momentarily inflated readings. If you consistently exceed the estimate during hard efforts, your true MHR is likely higher — adjust your zones accordingly.
How often should I recalculate my maximum heart rate?
Since MHR decreases by roughly 1 bpm per year of aging, recalculating annually when following an age-based formula is reasonable. Your resting heart rate can change more quickly with changes in fitness, so if you track Karvonen zones, update your resting HR every few months by measuring it first thing in the morning over several consecutive days and averaging the results.
Do women and men have different maximum heart rates?
The original age-based formulas were derived largely from male subjects. Research suggests women may have a slightly higher MHR on average for a given age, though the difference is modest (around 6–8 bpm at midlife). Some studies recommend the formula 206 − (0.88 × age) for women. For most practical training purposes, the Tanaka formula performs acceptably for both sexes.
Last updated: 2025-01-30 · Formula verified against primary sources.