Uses the Tanaka formula (208 − 0.7×age) for max heart rate, and the Karvonen method for target zones when resting heart rate is provided. Estimate only — consult a doctor before starting an intense exercise program.
What is a heart rate calculator, and who needs it?
Your maximum heart rate is the highest number of beats per minute your heart can reach during hard exercise. This calculator estimates it from your age, then divides it into three effort zones: moderate, vigorous and peak. If you also enter your resting heart rate, the zones are adjusted to your own fitness level.
It is useful for people who walk, jog, cycle, swim or play sports such as badminton and cricket, for gym beginners, and for anyone returning to exercise after a break. If you wear a fitness band or smartwatch, it also helps you understand what the numbers on your wrist actually mean.
Formula used
- Maximum heart rate = 208 − (0.7 × age), known as the Tanaka formula
- Heart rate reserve = Maximum heart rate − Resting heart rate
- Zone limit (with resting rate, Karvonen method) = Reserve × intensity + Resting heart rate
- Zone limit (without resting rate) = Maximum heart rate × intensity
- Intensity ranges: moderate 50% to 70%, vigorous 70% to 85%, peak 85% to 100%
Worked example
Take a 50-year-old with a resting heart rate of 65 bpm. Maximum heart rate = 208 − (0.7 × 50) = 208 − 35 = 173 bpm. Heart rate reserve = 173 − 65 = 108.
Moderate zone: 108 × 0.5 + 65 = 119 bpm to 108 × 0.7 + 65 = about 141 bpm. Vigorous zone: about 141 to 108 × 0.85 + 65 = about 157 bpm. Peak zone: about 157 to 173 bpm. So a brisk morning walk should keep this person between 119 and 141 bpm. For comparison, the older 220 − age rule would give 170 bpm, only 3 beats lower.
Frequently asked questions
What heart rate should I aim for during exercise?
It depends on your goal. Moderate effort (50 to 70 percent) suits brisk walking and easy cycling, vigorous effort (70 to 85 percent) suits running and sports, and peak effort above 85 percent should be used only briefly by people who are already fit.
Why does this calculator use 208 minus 0.7 times age instead of 220 minus age?
The Tanaka formula comes from analysing many studies, and it tends to be more accurate for adults over 40, where 220 minus age can under-estimate. Both are averages, so your real maximum may differ by 10 beats or more.
What is a normal resting heart rate?
For most adults it is between 60 and 100 beats per minute. Regular exercisers often have lower values. For the best reading, count your pulse for a full minute right after waking, before tea or coffee.
Do I have to enter my resting heart rate?
No, it is optional. Without it, the zones are simple percentages of your maximum. With it, the calculator uses the Karvonen method, which adjusts the zones to your own fitness level and is usually more personal.
Can I use these zones if I have a heart condition or take medicines?
Check with your doctor first. Medicines such as beta-blockers lower your heart rate, so age-based estimates can be misleading. If you feel chest pain, dizziness or unusual breathlessness, stop exercising and seek medical help.
Limitations and accuracy
The maximum heart rate is a population average estimated from age alone. Genetics, fitness, medicines, heat, stress, caffeine and lack of sleep all change your real numbers. The only way to measure true maximum heart rate is a supervised stress test. The calculator uses three broad zones and does not give a training plan. This tool is for information only and is not medical advice.