Target Heart Rate Calculator (Karvonen)
The Karvonen method personalises training zones by factoring in your resting heart rate, not just your age. It tends to give slightly higher target rates than the straight percentage-of-max approach, especially for fit people with low resting rates.
Enter your age and resting heart rate (measured first thing in the morning). The calculator returns your target range at 50–85% intensity.
It suits people who already know their resting heart rate and want training zones tuned to their starting fitness, rather than a one-size estimate from age alone.
Enter your values to see the result.
How this is calculated
The Karvonen method personalises training zones by factoring in your resting heart rate, not just your age. It first estimates your maximum heart rate as 220 minus your age, then computes your heart-rate reserve as max minus resting. The target rate at a given intensity is (max − resting) × intensity + resting, where intensity is a decimal between 0 and 1. This calculator reports the range at 50–85% intensity.
Because it adds resting heart rate back in, Karvonen tends to give slightly higher target rates than a straight percentage of max, especially for fit people with low resting rates. A lower resting heart rate generally means a larger reserve and higher target zones.
The model relies on the 220-minus-age estimate for max heart rate, which is a rough average with large individual variation. It does not account for medications that affect heart rate, cardiac conditions, heat, dehydration, or overtraining. Measure resting heart rate seated and still, ideally over several mornings, for a stable input. Use the result alongside perceived effort, not as an absolute ceiling.
Worked example
A 30-year-old with a resting heart rate of 60 bpm.
- 1Max heart rate = 220 − 30 = 190 bpm.
- 2Heart-rate reserve = 190 − 60 = 130 bpm.
- 3Lower target (50%) = 130 × 0.50 + 60 = 125 bpm; upper target (85%) = 130 × 0.85 + 60 ≈ 171 bpm.
Frequently asked questions
- How do I measure resting heart rate?
- Measure your pulse for 60 seconds while sitting still, ideally in the morning before getting up. Average several mornings for a stable value.
- How does Karvonen differ from percentage of max?
- Karvonen uses the heart-rate reserve (max minus resting) and adds resting back: Target = (Max − Resting) × intensity + Resting. It accounts for your starting fitness.
- What intensity should I aim for?
- 50–70% suits beginners and recovery; 70–85% suits steady aerobic training. Higher intensities are for intervals and advanced conditioning.
- How do I measure resting heart rate?
- Measure your pulse for 60 seconds while sitting still, ideally in the morning before getting up. Average several mornings for a stable value, since a single reading can be skewed by stress, caffeine or poor sleep.
- How does Karvonen differ from percentage of max?
- Karvonen uses the heart-rate reserve (max minus resting) and adds resting back: target = (max − resting) × intensity + resting. It accounts for your starting fitness, giving slightly higher zones for people with low resting rates.
Related calculators
Method: Karvonen heart-rate reserve formula. No external data source. Last updated: September 2026.
These results are general estimates from established formulas and are not medical advice. They depend on the accuracy of the values you enter and on individual factors the formulas cannot capture. Consult a qualified healthcare professional before making decisions about your diet, training or treatment.