What is maximum heart rate?
Maximum heart rate (HRmax) is the highest number of times your heart can beat per minute during intense exercise. It serves as the reference point for calculating heart rate training zones, helping athletes and fitness enthusiasts train at the right intensity. Your HRmax is primarily determined by age and is largely independent of fitness level or gender.
How do you calculate maximum heart rate?
The three most widely used formulas are:
- Classic formula (Fox, 1971): HRmax = 220 − age — the most familiar method, simple but can over- or underestimate by 10–20 bpm, especially for older adults.
- Tanaka formula (2001): HRmax = 208 − (0.7 × age) — derived from a meta-analysis of 351 studies; more accurate for adults over 40 and considered the preferred formula by exercise scientists.
- HUNT formula (Nes et al., 2013): HRmax = 211 − (0.64 × age) — based on 3,320 healthy adults aged 19–89 in the HUNT Fitness Study; shows no interaction with gender, activity level, or BMI and is considered the most accurate for the general population.
For example, a 35-year-old gets: Classic = 185 bpm, Tanaka = 184 bpm, HUNT = 189 bpm. To find your training zones, pair these numbers with our calorie calculator to estimate total energy expenditure.
What are the five heart rate training zones?
Training zones divide exercise intensity into five bands based on your maximum heart rate:
- Zone 1 (50–60% HRmax) — Light: Recovery and warm-up. Comfortable effort; builds aerobic base.
- Zone 2 (60–70% HRmax) — Fat Burn: Moderate effort; approximately 65% of calories burned come from fat. Ideal for long-duration training.
- Zone 3 (70–80% HRmax) — Aerobic: Sustained cardio effort; improves cardiovascular fitness and endurance.
- Zone 4 (80–90% HRmax) — Anaerobic: High intensity; improves lactate threshold and speed.
- Zone 5 (90–100% HRmax) — Maximum: All-out effort; short intervals only; develops maximum speed and power.
What are some maximum heart rate examples?
Using the classic formula (220 − age):
- Age 25: HRmax = 195 bpm. Zone 3 (aerobic) = 137–156 bpm.
- Age 35: HRmax = 185 bpm. Zone 2 (fat burn) = 111–130 bpm.
- Age 45: HRmax = 175 bpm. Zone 4 (anaerobic) = 140–158 bpm.
- Age 55: HRmax = 165 bpm. Zone 1 (light) = 83–99 bpm.
Using the Tanaka formula (208 − 0.7 × age) for age 50: HRmax = 208 − 35 = 173 bpm — about 4 bpm lower than the classic formula for the same age, reflecting better accuracy for older adults.
How accurate is the 220-minus-age formula?
The 220−age formula has a standard deviation of 10–12 bpm, meaning your true maximum heart rate could be 10–20 bpm higher or lower than predicted. It was never validated in a controlled study — it originated from informal observations in 1971. Two people of the same age can differ by up to 30 bpm in actual HRmax. The Tanaka formula reduces this error somewhat for adults over 40, while the HUNT formula (standard error of 10.8 bpm) provides the best population-wide accuracy based on the largest controlled study. The most accurate method remains a maximal exercise stress test performed by a cardiologist or exercise physiologist. For everyday training planning, age-based estimates are practical and sufficient; combine them with our running pace calculator to build structured workouts.
What factors affect maximum heart rate?
Age is the dominant factor — HRmax declines roughly one beat per year after the mid-twenties. Other influences include genetics (the largest individual variable), altitude (HRmax is lower at altitude), heat and humidity (cardiovascular stress increases), certain medications (beta-blockers significantly lower HRmax), and overtraining (a suppressed HRmax can signal fatigue). Fitness level itself has minimal direct effect on HRmax but greatly influences how efficiently you operate at each percentage of it. To see how HRmax interacts with other health metrics, visit our BMI calculator.
Which heart rate zone burns the most fat?
Zone 2 (60–70% of HRmax) is often called the "fat-burning zone" because the proportion of calories coming from fat is highest here — around 65%. However, higher zones burn more total calories per minute. For overall fat loss, a combination of Zone 2 endurance sessions and higher-intensity Zone 4 intervals is more effective than staying exclusively in the fat-burning zone.