Heart Rate Zones Calculator
Calculate all 5 training zones
The Heart Rate Zones Calculator helps you optimize your training by defining specific intensity levels associated with your maximum heart rate. Whether you want to burn fat, build endurance, or improve peak performance, training in the right zone is key.
Formula
Max HR = 220 - Age
Zones = % of Max HR
The 5 Zones
| Z1 Recovery | 50-60% |
| Z2 Fat Burn | 60-70% |
| Z3 Aerobic | 70-80% |
| Z4 Threshold | 80-90% |
| Z5 Maximum | 90-100% |
Related
Ultimate Guide to Heart Rate Zones
Heart rate zone training is a methodology that uses your heart rate to define the intensity of a workout. Instead of training based on "feel" or random pace, you use objective biometric data to ensure you are stimulating the right energy systems.
The 5 Training Zones
- 🟢 Zone 1 (50-60% Max HR): Recovery. Very light effort. Used for warming up, cooling down, and active recovery days.
- 🔵 Zone 2 (60-70% Max HR): Endurance & Fat Burn. The "sweet spot" for building aerobic base. You can hold a conversation here. Trains your body to burn fat for fuel.
- 🟡 Zone 3 (70-80% Max HR): Aerobic. Moderate effort. Improves blood circulation and skeletal, muscle strength. Often called the "Grey Zone" – be careful not to spend all your time here.
- 🟠 Zone 4 (80-90% Max HR): Threshold. Hard effort. Sustainable for shorter periods (10-60 mins). Increases your lactate threshold and tolerance for high-intensity work.
- 🔴 Zone 5 (90-100% Max HR): VO2 Max. Maximum effort. Sprints and very short intervals. Develops top-end speed and neuromuscular power.
Why Zone 2 is Critical
Elite endurance athletes spend nearly 80% of their training time in Zone 2. This builds a massive "aerobic engine" without causing excessive fatigue, allowing them to train more frequently and harder on their high-intensity days.
Frequently Asked Questions
Zone 2 (60-70% max HR) is often cited as the 'fat-burning zone' because a higher percentage of calories burned comes from fat. However, higher intensity zones burn more total calories. For weight loss, a mix of Zone 2 for duration and higher zones for intensity is effective.
The most common formula is 220 minus your age. This provides a general estimate. For a more personalized number, a graded exercise test performed by a professional is recommended.
Zone 2 training involves exercising at 60-70% of your max heart rate. It is a pace where you can hold a conversation. It builds your aerobic base, improves mitochondrial efficiency, and is crucial for endurance performance.
If you are new to running, your heart rate may spike easily. This is normal. As your cardiovascular fitness improves through consistent training, your heart rate at a given pace will decrease (become more efficient).
Zone 5 (90-100% max HR) is very intense and stressful on the body. It should be used sparingly, typically for short intervals during 1-2 sessions per week for experienced athletes, with ample recovery time.
References
Zone definitions and training principles are based on sports cardiology standards:
- American Heart Association (AHA). "Target Heart Rates Chart".
- Mayo Clinic. "Exercise intensity: How to measure it".
- Karvonen, J., & Vuorimaa, T. (1988). "Heart rate and exercise intensity during sports activities". Sports Medicine.