Target Heart Rate Calculator — Training Zones
Calculate your maximum heart rate and target heart rate training zones for fat burning, aerobic conditioning, and peak performance.
Understanding Heart Rate Training Zones
Training at specific heart rate intensities produces distinct physiological adaptations. By monitoring your heart rate during exercise, you can ensure you're training at the appropriate intensity for your specific goal — whether that's burning fat, improving cardiovascular fitness, or maximizing performance.
Karvonen formula (more personalized):
Target HR = ((Max HR − Resting HR) × intensity%) + Resting HR
The 5 Heart Rate Training Zones
| Zone | % Max HR | Feeling | Primary Benefit |
|---|---|---|---|
| Zone 1 (Recovery) | 50–60% | Very easy, conversational | Active recovery, warm-up |
| Zone 2 (Fat Burn) | 60–70% | Easy, can hold conversation | Fat oxidation, aerobic base |
| Zone 3 (Aerobic) | 70–80% | Moderate, slightly breathless | Cardiovascular fitness, endurance |
| Zone 4 (Threshold) | 80–90% | Hard, difficult to speak | Lactate threshold, speed |
| Zone 5 (VO2 Max) | 90–100% | Maximum effort | Speed, peak power output |
The "Fat Burning Zone" Myth
While Zone 2 burns the highest percentage of calories from fat, Zone 3–4 burns more total calories, including more total fat in absolute terms. For weight loss, total calorie deficit matters more than the fuel source ratio. Zone 2 training is valuable for building aerobic base and recovery capacity, not because it uniquely burns fat.
Resting Heart Rate as a Fitness Marker
A normal resting heart rate is 60–100 bpm. Highly trained endurance athletes often have resting heart rates of 40–50 bpm. A lower resting HR generally indicates a more efficient heart that pumps more blood per beat. Monitoring your morning resting HR over weeks can also serve as an early indicator of overtraining or illness.