Heart Rate Zone Calculator
Calculate personalized training zones using the Karvonen method
What This Calculator Measures
This calculator determines your five heart rate training zones using the Karvonen method, which accounts for both your age-predicted maximum heart rate and your resting heart rate. Training in different zones produces different physiological adaptations.
How It Works
**Max HR = 220 - Age**
**Target HR = ((Max HR - Resting HR) x Intensity%) + Resting HR**
The Karvonen method is more personalized than simple percentage-of-max formulas because it uses your Heart Rate Reserve (HRR), which accounts for your fitness level through resting heart rate.
| Zone | Intensity | Name | Purpose |
|---|---|---|---|
| Zone 1 | 50-60% | Recovery | Active recovery, warm-up, cool-down |
| Zone 2 | 60-70% | Fat Burn / Base | Base endurance, fat oxidation, aerobic foundation |
| Zone 3 | 70-80% | Aerobic | Improved cardiovascular efficiency |
| Zone 4 | 80-90% | Threshold | Lactate threshold, anaerobic capacity |
| Zone 5 | 90-100% | Max Effort | VO2max, peak power output |
Zone 2 for Lifters
Zone 2 cardio (the "fat burn" zone) has gained significant attention as the optimal intensity for cardiovascular health without interfering with strength training recovery. 2-3 sessions of 30-45 minutes per week at Zone 2 intensity builds aerobic capacity, improves recovery between sets, and supports heart health without the recovery cost of high-intensity cardio.
Limitations
Frequently Asked Questions
- What are heart rate training zones?
- Five zones from easy to max effort, each based on a percentage of your max heart rate. Zone 1-2 is easy cardio and fat burning. Zone 3 is moderate cardio. Zone 4-5 is high intensity and anaerobic. Different zones train different energy systems.
- What is the Karvonen method?
- It's a more accurate way to calculate heart rate zones because it factors in your resting heart rate, not just your max. Someone with a resting HR of 55 and someone with 75 will get different zone ranges even if they're the same age. It personalizes the zones to your fitness level.
- Which heart rate zone burns the most fat?
- Zone 2 (60-70% of max HR) burns the highest percentage of calories from fat. But Zone 4-5 burns more total calories per minute. For fat loss, total calorie burn matters most, so higher intensity is actually more time-efficient. The "fat burning zone" on treadmills is misleading.
- Do I need a heart rate monitor to use training zones?
- It helps, but you can use perceived effort as a rough guide. Zone 2 feels like you can hold a full conversation. Zone 3, you can talk in short sentences. Zone 4, you can only say a few words. Zone 5, you can't talk at all.