Why Your Age Sets Your Heart Rate Zones
Maximum heart rate — the fastest your heart can beat during all-out effort — declines gradually with age. That is why most heart rate training plans start from your age. Once you know your estimated maximum, you can divide your effort into zones, each with a different training effect, from gentle recovery to short, intense intervals.
Estimating maximum heart rate
The well-known 220 − age formula is easy to remember but was never based on rigorous research. In 2001, Hirofumi Tanaka and colleagues analysed data from hundreds of studies and proposed 208 − 0.7 × age, which tends to be more accurate, particularly for older adults. Both are population averages: an individual's true maximum can differ by 10 beats per minute or more.
| Age | 220 − age | Tanaka (208 − 0.7 × age) |
|---|---|---|
| 20 | 200 | 194 |
| 30 | 190 | 187 |
| 40 | 180 | 180 |
| 50 | 170 | 173 |
| 60 | 160 | 166 |
| 70 | 150 | 159 |
The Karvonen method
If you know your resting heart rate, the Karvonen formula personalises your zones using your heart rate reserve — the difference between your maximum and resting rates:
Because a fitter heart usually beats more slowly at rest, the Karvonen method gives fitter people slightly higher training targets, which better reflects their actual effort.
What each zone does
- Zone 1 (50–60%) — warm-ups, cool-downs and active recovery.
- Zone 2 (60–70%) — comfortable, conversational pace that builds aerobic endurance; the backbone of most endurance training plans.
- Zone 3 (70–80%) — steady, moderately hard aerobic work.
- Zone 4 (80–90%) — threshold training; hard but sustainable for limited periods.
- Zone 5 (90–100%) — very short, maximal intervals.
How much exercise?
The World Health Organization recommends that adults get at least 150–300 minutes of moderate-intensity aerobic activity, or 75–150 minutes of vigorous activity, each week, plus muscle-strengthening activities on two or more days. The moderate and vigorous ranges shown in the results help you check you are working hard enough to count.
If you are new to exercise, have a heart condition, take medication that affects heart rate (such as beta blockers) or experience chest pain, dizziness or unusual breathlessness, speak to a doctor before training by heart rate.
Frequently Asked Questions
Which max heart rate formula is best?
No age-based formula is perfect, but research suggests the Tanaka formula (208 − 0.7 × age) is more accurate than 220 − age, especially after age 40. A supervised exercise test gives the most accurate personal value.
What is the 'fat-burning zone'?
Lower intensities (around Zones 1–2) use a higher percentage of fat for fuel, but higher intensities burn more total calories per minute. For weight management, total weekly activity matters more than the zone.
What is a normal resting heart rate?
For most adults, a resting heart rate between 60 and 100 bpm is considered normal. Well-trained athletes often have resting rates in the 40s or 50s.
Why does my watch show different zones?
Fitness trackers may use different formulas, your measured maximum or heart rate reserve. Small differences between methods are normal.
Disclaimer: This calculator provides general information only and is not a substitute for professional medical advice, diagnosis or treatment. Formulas are population averages and may not fit your individual situation. Always consult a qualified healthcare provider about your health.
Related tools