Transparent method
The formula
Worked example
Example inputs
How to interpret the result
The Karvonen method's target heart rate zone is built from a formula using age and resting heart rate, and real heart-rate response can shift meaningfully from that formula's prediction due to medication, fitness level or an underlying health condition, which is exactly why the zone is a starting estimate rather than a precise personal prescription.
Before you rely on it
What to check
Compare the formula's zone against how you actually feel during training, and adjust based on real response rather than treating the calculated zone as an exact, unchangeable target.
The common error
Where people go wrong with target heart rate calculator
Treating a formula-derived heart-rate zone as a precise personal prescription regardless of medication or health conditions. Beta blockers and certain other medications specifically can blunt heart-rate response in a way the formula has no way to account for.
Sensitivity evidence
How age changes the target heart rate
| Age | Target heart rate | Estimated maximum heart rate |
|---|---|---|
| 17.0 years | 161.6 | 203 |
| 26.0 years | 155.3 | 194 |
| 35.0 yearsworked example | 149 | 185 |
| 44.0 years | 142.7 | 176 |
| 53.0 years | 136.4 | 167 |
Every input, tested
Which input moves the target heart rate most
| Input | Tested from | To | Target heart rate at each end | Swing |
|---|---|---|---|---|
| Age | 26.0 years | 44.0 years | 155.3 to 142.7 | 12.6 (8.5%) |
| Target intensity | 68.0% | 72.0% | 146.6 to 151.4 | 4.8 (3.2%) |
| Resting heart rate | 59 | 72 | 147.2 to 151.1 | 3.9 (2.6%) |
Two variables at once
Target heart rate by age and resting heart rate
| Age \ Resting heart rate | 52 | 65 | 78 |
|---|---|---|---|
| 17.0 years | 157.7 | 161.6 | 165.5 |
| 26.0 years | 151.4 | 155.3 | 159.2 |
| 35.0 years | 145.1 | 149 | 152.9 |
| 44.0 years | 138.8 | 142.7 | 146.6 |
| 53.0 years | 132.5 | 136.4 | 140.3 |
Step by step
The worked example, input by input
| Input | Value used | What it means |
|---|---|---|
| Age | 35.0 years | Age in years. |
| Resting heart rate | 65 | Measured at rest, in beats per minute. |
| Target intensity | 70.0% | Percent of heart-rate reserve. |
| Target heart rate | 149 | |
| Estimated maximum heart rate | 185 | |
Inputs, definitions and assumptions
Age
Age in years.
Resting heart rate
Measured at rest, in beats per minute.
Target intensity
Percent of heart-rate reserve.
Where the inputs come from
Enter your age, your resting heart rate and the intensity you want, as a percent of heart rate reserve. Measure resting heart rate in the morning before getting out of bed, counting beats for 60 seconds, and average three days. The Karvonen method uses heart rate reserve, which is estimated maximum minus resting rate, so the target reflects fitness. Choose 50% to 70% for moderate exercise and 70% to 85% for vigorous exercise.
When the result stops applying
The maximum heart rate from age is an estimate with a standard deviation of about 10 beats per minute, so your true maximum may differ. Medications such as beta blockers lower heart rate, and caffeine, heat and stress raise it. People with heart conditions should follow medical guidance. Wearable monitors add error.
What to compare it with
See the maximum heart rate calculator for alternative formulas, and the VO2 max and running pace pages for fitness and pacing. The calories burned page estimates energy use. A doctor can advise on safe heart rate limits.
People also ask
Frequently asked questions
How do I find my resting heart rate?
Count your pulse for a full minute when you wake up, before getting out of bed, and average several days.
What is the Karvonen method?
It sets target heart rate as a percentage of heart rate reserve, the gap between maximum and resting heart rate, and then adds back the resting rate.
Do heart rate zones matter for everyone?
They are a helpful guide, but perceived effort, such as being able to talk in moderate exercise, is also a reliable measure.