Karvonen Target Heart Rate Calculator
Use the Karvonen method to estimate your personalized training zone based on your age, resting heart rate, and workout intensity.
What is the Karvonen heart rate formula?
The Karvonen formula is a popular way to calculate exercise intensity using your heart rate reserve (HRR). Unlike a simple “percent of max heart rate” approach, Karvonen includes your resting heart rate, which helps make training targets more personal and useful.
The core idea is straightforward:
- Estimate your maximum heart rate (HRmax)
- Subtract resting heart rate (RHR) to get heart rate reserve
- Apply your desired intensity percentage
- Add resting heart rate back in
Karvonen equation
Target HR = ((HRmax − RHR) × Intensity) + RHR
Where intensity is written as a decimal (for example, 70% = 0.70).
Why this method is useful for training
Two people can be the same age but have very different resting pulse values. If both follow the same generic heart rate target, one may train too hard and the other too easy. Karvonen adjusts for this by using your own baseline (resting heart rate).
That makes it useful for:
- Cardio beginners who want safer pacing
- Runners and cyclists building aerobic fitness
- Weight loss programs using steady-state cardio
- Athletes structuring zone-based training
How to choose your intensity zone
Typical ranges
- 50–60%: Recovery / very easy movement
- 60–70%: Endurance base and fat oxidation
- 70–80%: Aerobic conditioning and tempo work
- 80–90%: High-intensity intervals
- 90–100%: Near-max effort (advanced athletes only)
If you are new to exercise, starting in the 55–70% range is usually more sustainable and safer.
Step-by-step example
Let’s say your numbers are:
- Age: 40
- Resting HR: 65 bpm
- Intensity goal: 60% to 75%
Using traditional HRmax:
HRmax = 220 − 40 = 180
HRR = 180 − 65 = 115
At 60%: ((115 × 0.60) + 65) = 134 bpm
At 75%: ((115 × 0.75) + 65) = 151 bpm
Your target zone would be roughly 134–151 bpm.
Practical tips for better accuracy
- Measure resting pulse on multiple mornings and average it.
- Use a chest strap monitor if possible for better real-time accuracy.
- Recalculate every few months as fitness improves.
- If you know your lab-tested max HR, use custom mode in the calculator.
Important safety note
This calculator is for educational and fitness planning purposes, not diagnosis or treatment. If you have a cardiovascular condition, are on heart medication, or are returning after illness, consult your physician before using heart-rate-guided training.