How to use it
- Type your Age.
- Enter your Resting heart rate from a morning measurement. The Karvonen method needs it.
- If you have a measured value, enter it as Maximum heart rate (optional); otherwise leave it empty and the page estimates it.
- Choose a Method and read the Heart rate at each intensity table to find the row for your planned effort.
How the maximum heart rate is estimated
The calculator uses the formula from Tanaka, Monahan and Seals (2001). Their meta-analysis of 351 studies with 18,712 subjects found that the maximum heart rate follows 208 minus 0.7 times age in healthy adults. The formula gives an average for people of the same age; your own maximum can be higher or lower.
A formula is no substitute for a measurement. For anyone with a heart condition, a doctor or a supervised test sets the safe upper limit. This page is not medical advice.
HRmax = 208 − 0.7 × age
For age 40: 208 − 0.7 × 40 = 180 beats per minuteKarvonen and percent of maximum
The Karvonen method measures intensity as a share of the heart rate reserve: the gap between the maximum and the resting heart rate. The resting rate is added back at the end, so a fitter person with a lower resting rate gets a wider range.
The percent method takes the intensity as a share of the maximum heart rate alone. It does not need the resting heart rate.
Karvonen: (HRmax − HRrest) × intensity + HRrest
Percent: HRmax × intensityWhat this calculator does not include
- Named training zones such as zone 2 or zone 4. Their boundaries differ between coaches and textbooks, so this page shows the heart rate at each intensity only. Use the boundaries your coach or doctor uses.
- Medicines such as beta-blockers, heat, caffeine, stress, illness and tiredness, which all change the heart rate on a given day.
- Heart rhythm problems and diagnosed heart disease, which need a medical assessment.
Worked example: age 40, resting 60, Karvonen
The maximum heart rate is 208 − 0.7 × 40 = 180 beats per minute. The heart rate reserve is 180 − 60 = 120.
At 70 percent intensity the target is 120 × 0.70 + 60 = 144 beats per minute.
| Intensity | Beats per minute |
|---|---|
| 50% | 120 |
| 60% | 132 |
| 70% | 144 |
| 80% | 156 |
| 90% | 168 |
Frequently asked questions
How can I find my real maximum heart rate?
The most accurate way is a maximal exercise test supervised by a doctor or a trained tester. The formula gives an average for people of your age, and your own maximum can be higher or lower.
Which method should I choose, Karvonen or percent of maximum?
If you know your resting heart rate, the Karvonen method takes it into account and is the more personal of the two. If you do not know it, use the percent method.
Why is 220 minus age still shown?
It is an older and very common shortcut. Tanaka and colleagues (2001) concluded that it likely underestimates the maximum in older adults, so the page shows it only for comparison.
What if my heart rate is different from the table?
The table is an estimate. Heat, sleep, caffeine, stress and some medicines change your heart rate, so also watch your breathing and how hard the effort feels.
Is this calculator medical advice?
No. It gives a general estimate for planning. If you have chest pain, dizziness or a known heart condition, ask your doctor before you start or increase training.
Sources
- Tanaka, Monahan and Seals (2001): Age-predicted maximal heart rate revisited, J Am Coll Cardiol 37(1):153-156
- Wikipedia: Heart rate reserve (the Karvonen formula, from Karvonen's 1957 study)
Figures and text last checked on Tuesday, November 10, 2026.