Heart Rate Zone Calculator
Your maximum heart rate and the five training zones, from your age.
Good to know. Zone 2 feels almost too easy, which is exactly why most runners train too hard in it.
Not medical advice. A general estimate for healthy adults.
How it works
In plain words
Estimate your maximum heart rate from your age. Each zone is a band of 10% of that maximum, from 50% to 100%. If you enter a resting heart rate, the zones are worked out on the range between resting and maximum instead (the Karvonen method).
The formula
max = 208 − 0.7 × age (or 220 − age) zone = max × % Karvonen: zone = resting + (max − resting) × %
Worked example
At 40, the maximum heart rate is about 208 − 0.7 × 40 = 180 bpm. Zone 2, at 60–70% of that, is 108–126 bpm.
Sources
- Tanaka, Monahan and Seals, Age-predicted maximal heart rate revisited, Journal of the American College of Cardiology, 2001 The formula 208 − 0.7 × age.
- American Heart Association, Target heart rates chart Moderate and vigorous exercise ranges.
- Karvonen, Kentala and Mustala, The effects of training on heart rate, Annales Medicinae Experimentalis et Biologiae Fenniae, 1957 Zones from the heart rate reserve.
Sources checked September 30, 2026. 5 automated tests check its answers on every change.
About the heart rate zone calculator
Heart rate zones turn “go easy” and “push hard” into numbers you can see on a watch. They are bands of effort based on your maximum heart rate, the fastest your heart can beat. Most training plans use five zones, from a gentle warm-up in zone 1 to an all-out sprint in zone 5.
Your maximum heart rate is estimated from your age. The familiar 220 − age is simple but tends to underestimate it for older adults. The formula 208 − 0.7 × age, from a 2001 analysis of 351 studies, is more accurate across ages and is the default here. Either way, individuals can differ by 10 beats or more, so a lab or field test gives a truer figure.
If you know your resting heart rate, enter it. The Karvonen method then places the zones between your resting and maximum rate, which suits fitter people with a low resting pulse better.
Most endurance training happens in zone 2, where you can still hold a conversation: it builds stamina with little strain. Health guidelines recommend at least 150 minutes a week of moderate activity (50–70% of your maximum) or 75 minutes of vigorous activity (70–85%). If you take heart medication such as beta blockers, or have a heart condition, ask your doctor for targets.
Questions people ask
What is my maximum heart rate?
About 208 − 0.7 × your age. At 40, that is about 180 beats per minute; 220 − age gives a similar 180.
What is zone 2 heart rate?
60–70% of your maximum heart rate: at 40, about 108 to 126 bpm. You can still talk in full sentences.
What is the fat-burning zone?
Zones 2 and 3, where a larger share of the energy comes from fat. Harder exercise burns more calories in total, and it is the total that counts for weight loss.