Karvonen Target Heart Rate Calculator
Use the Karvonen formula to personalize training zones. Enter your age, resting heart rate, and workout intensity to get target heart rates for warm-ups, fat burning, and anaerobic sessions.
Inputs
Example: enter 0.70 for 70% intensity.
Karvonen Results
Estimated max heart rate
190 bpm
Calculated as 220 − age. Use lab-tested max if available.
Heart rate reserve
130 bpm
HRR = HRmax − HRrest.
Selected intensity target
151 bpm
70% intensity session target.
Training zone range
138 – 164 bpm (60% – 80% intensity)
Heart Rate Zones
| Zone | Intensity | Target HR (bpm) | Description |
|---|---|---|---|
| Light warm-up | 50% | 125 bpm | Gentle pacing, conversational breathing. |
| Fat-burning | 60% | 138 bpm | Comfortable aerobic training. |
| Aerobic endurance | 70% | 151 bpm | Improves cardiovascular capacity. |
| Hard training | 80% | 164 bpm | Challenging but sustainable intervals. |
| Anaerobic power | 90% | 177 bpm | High intensity, short bursts. |
| VO₂ max effort | 95% | 184 bpm | Maximum sustainable effort for athletes. |
How to Use This Calculator
Measure resting heart rate
Count beats per minute first thing in the morning or after 5 minutes of seated rest. Use a chest strap or ECG for greatest accuracy.
Set your intensity
Choose an intensity that matches your workout goal—lower for recovery, higher for intervals. Create a range to track target zones.
Monitor during exercise
Use a heart rate monitor to stay within your target zone. Adjust pace, resistance, or incline to raise or lower heart rate as needed.
Formula
Target HR = (HRmax − HRrest) × Intensity + HRrest
- HRmax is estimated as 220 − age (or use lab-tested max if available).
- Intensity is expressed as a decimal (e.g., 0.7 for 70%).
- Karvonen formula leverages heart rate reserve to tailor training zones.
Example: Age 35, HRrest 62 bpm, intensity 0.75 → HRmax = 185 bpm → Target HR ≈ 62 + (123 × 0.75) = 155 bpm.
Why Train with Karvonen Zones?
The Karvonen method accounts for individual fitness by subtracting resting heart rate from maximum heart rate. This yields more personalized zones than percentage of max heart rate alone—especially useful for trained athletes with lower resting heart rates.
Use the calculated zones to structure workouts: start in lower zones for warm-ups, progress to mid-zones for steady-state cardio, and reserve higher zones for interval training. Monitor response and adjust as fitness improves.
Frequently Asked Questions
Is 220 − age accurate for everyone?
It is an estimate. Use treadmill stress tests or wearable data to find your personal max heart rate for more accuracy.
What if my resting heart rate changes?
Recalculate as your fitness improves. Lower resting heart rates will shift zones slightly downward for the same intensity.
Can I input intensity as a percentage?
Convert percentage to decimal (e.g., 70% → 0.70). We show the percentage in the results for convenience.
Who should avoid high intensities?
People with cardiovascular conditions should consult their physician. Always follow medical advice before high-intensity training.