Karvonen formula: target heart rate for health-enhancing physical activity

The Karvonen formula is a calculation method developed in 1957 by the Finnish exercise physiologist Martti Karvonen. It is used to guide exercise intensity and to plan training. The formula calculates the heart rate reserve, i.e. the difference between maximum heart rate and resting heart rate, and the target heart rate is expressed as a percentage of the heart rate reserve. This way the calculation takes your individual fitness level into account.

To use the calculator, you need your maximum heart rate and your resting heart rate. If you do not know your maximum heart rate, you can work it out with a maximum heart rate calculator.

You can measure your resting heart rate, for example, by counting your heartbeats at rest for 15 seconds while lightly feeling your pulse with your fingertips on your wrist or neck. Multiply the number of beats by four to get your resting heart rate in beats per minute. In most adults the resting heart rate is 60–100 beats per minute, and in athletes it is often lower.

The Karvonen formula:

target heart rate = (maximum heart rate - resting heart rate)

\times exercise intensity (%) + resting heart rate

Example: if your maximum heart rate is 190, your resting heart rate is 60 and the exercise intensity is 60%, your target heart rate is (190 − 60) × 0.6 + 60 = 138.

The Karvonen formula is particularly suitable for estimating the intensity of health-enhancing physical activity. You can calculate heart rate zones for endurance training and estimates of the aerobic and anaerobic thresholds with the heart rate zone calculator.

Heart rate zones for health-enhancing physical activity

Light intensity

30–39% of heart rate reserve
breathing barely speeds up
suitable for getting started with exercise and for recovery
example: easy walking

Moderate intensity

40–59% of heart rate reserve
breathing speeds up, but you can still talk
supports health
example: brisk walking

Vigorous intensity

60–89% of heart rate reserve
breathing speeds up clearly and talking is difficult
develops endurance fitness effectively
example: running or cross-country skiing

Maximal intensity

at least 90% of heart rate reserve
talking is very difficult
the intensity can only be maintained for a short time
example: hard intervals

Physical activity recommendation

Do at least 150 minutes of moderate-intensity physical activity per week.

Do at least 75 minutes of vigorous-intensity physical activity per week.

You can also combine moderate-intensity and vigorous-intensity activity.

Published: 14.10.2026

Updated: 14.10.2026

The text is a translation from the original Finnish-language text.

Author of the original text

Lassi Honkanen
physiotherapist

Sources:

Ignaszewski, M., Lau, B., Wong, S. & Isserow, S. 2017. The science of exercise prescription: Martti Karvonen and his contributions. British Columbia Medical Journal. https://bcmj.org/articles/science-exercise-prescription-martti-karvonen-and-his-contributions

Karvonen, M. J., Kentala, E. & Mustala, O. 1957. The effects of training on heart rate; a longitudinal study. Annales Medicinae Experimentalis et Biologiae Fenniae, 35(3), 307–315.

Garber, C. E., Blissmer, B., Deschenes, M. R., Franklin, B. A., Lamonte, M. J., Lee, I.-M., Nieman, D. C. & Swain, D. P. 2011. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise. Medicine and Science in Sports and Exercise, 43(7), 1334–1359. https://doi.org/10.1249/MSS.0b013e318213fefb

World Health Organization. 2020. WHO guidelines on physical activity and sedentary behaviour. Geneva: World Health Organization. https://www.who.int/publications/i/item/9789240015128