Target Heart Rate Calculator
Find the heart-rate zones to train in, in beats per minute. Choose the simple %HRmax method the American Heart Association uses, or the Karvonen method, which factors in your resting heart rate to personalize the zones to your fitness.
Applies each intensity percentage straight to your estimated maximum heart rate.
Your target zones will appear here
Enter your age, pick a method, then click calculate to see your training heart-rate zones.
Quick Answer
Estimate your maximum heart rate as 220 minus your age, then aim for 50 to 85% of it during exercise: about 50 to 70% for moderate work and 70 to 85% for vigorous. The Karvonen method refines this by using your heart rate reserve (max minus resting) and adding your resting rate back on.
How It Works: Formula & Variables
Both methods start from an estimated maximum heart rate. The %HRmax method applies the intensity to that maximum directly; the Karvonen method routes it through your heart rate reserve so your resting pulse shapes the result.
HRmax ≈ 220 − age
%HRmax method: target = HRmax × intensity%
HRR = HRmax − resting heart rate
Karvonen: target = (HRR × intensity%) + resting heart rate
- Moderate (AHA)
- About 50–70% of HRmax.
- Vigorous (AHA)
- About 70–85% of HRmax.
- Overall zone
- The full training window sits at 50–85% of HRmax.
| ACSM zone | % of HRmax |
|---|---|
| Very light | <57% |
| Light | 57–63% |
| Moderate | 64–76% |
| Vigorous | 77–95% |
| Near-maximal to maximal | ≥96% |
Sources: American Heart Association, target heart rates, Karvonen formula (Topend Sports), and NASM heart rate zones (ACSM ranges).
Worked Examples
Example 1: %HRmax method, age 40
HRmax = 220 − 40 = 180 bpm. Moderate (50–70%): 180 × 0.50 = 90 up to 180 × 0.70 = 126, so 90–126 bpm. Vigorous (70–85%): 180 × 0.70 = 126 up to 180 × 0.85 = 153, so 126–153 bpm.
Example 2: Karvonen method, age 40, resting HR 80, 70% intensity
HRmax = 180. HRR = 180 − 80 = 100. Target = (100 × 0.70) + 80 = 70 + 80 = 150 bpm. Notice that the same 70% intensity gives 150 bpm by Karvonen versus 126 bpm by %HRmax, because Karvonen adds the resting rate back on.
Key Concepts
The same intensity, two numbers: %HRmax and Karvonen answer the same question differently. At the same percentage, Karvonen lands higher because it adds your resting rate back in.
Resting heart rate reflects fitness: a lower resting pulse usually means a fitter heart, which is exactly why Karvonen personalizes the zones and %HRmax does not.
220 − age is an average: it works well across a group but can miss for any one person. Use how the effort feels as a reality check on the numbers.
Pairs with pace: to combine effort and speed in your training, use the Running Pace Calculator alongside these zones.
Common Mistakes
Treating 220 − age as exact: the AHA presents it as a general guideline, an average rather than your personal maximum. Expect some spread.
Confusing %HRmax with %HRR: the same intensity percentage gives different beats per minute in each method. Keep track of which one you are using.
Starting at 85% as a beginner: the AHA advises new exercisers to work closer to the 50% end and build up gradually rather than jumping to the top of the range.
Guessing your resting heart rate: for Karvonen, a made-up resting number throws off every zone. Measure it after waking, ideally averaged over three mornings.
Frequently Asked Questions
For most adults, your target heart rate during exercise is roughly 50 to 85% of your maximum heart rate. The lower end suits easier, moderate sessions, and the upper end is for harder, vigorous efforts. This tool turns those percentages into actual beats per minute for your age.
The quick estimate is 220 minus your age. A 40-year-old would have an estimated maximum of about 180 beats per minute. It is an average across a population, so your real maximum can sit above or below it, but it is a reasonable starting point for setting zones.
The %HRmax method applies the intensity percentage straight to your maximum heart rate. The Karvonen method works from your heart rate reserve, which is your maximum minus your resting rate, then adds the resting rate back on. Because Karvonen factors in your resting pulse, it personalizes the zones to your fitness, and the two methods give different beats per minute for the same intensity.
The American Heart Association puts moderate intensity at about 50 to 70% of maximum heart rate, and vigorous intensity at about 70 to 85%. Moderate feels like brisk work you can still talk through, while vigorous is harder breathing where talking gets clipped.
Find your pulse on the inside of your wrist, below the thumb, count the beats for 30 seconds, and multiply by two. A chest strap or wrist monitor does the same job continuously, which is handy for staying in a zone while you train.
Karvonen is often the more accurate of the two because it accounts for your resting heart rate, which reflects your fitness. The %HRmax method is simpler and needs only your age, but it treats everyone of the same age the same, so it can be less precise for very fit or very unfit individuals.
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Medical disclaimer
For educational purposes only — not professional medical or nutrition advice. Consult a qualified professional before making dietary or exercise changes.
Sources: American Heart Association, Karvonen (Topend Sports), NASM / ACSM zones.