Heart Rate Zone Calculator
Calculate your target heart rate zones for training. Based on your age and resting heart rate using the Karvonen formula.
Understanding Heart Rate Zones
Heart rate training zones are calculated as percentages of your Maximum Heart Rate (MHR). The most common formula is: MHR = 220 - age. While simplified, it provides a useful baseline for training.
- Zone 1 (50-60% MHR): Very light — warm-up, recovery, fat burning
- Zone 2 (60-70% MHR): Light — base endurance, conversation pace
- Zone 3 (70-80% MHR): Moderate — aerobic fitness, marathon pace
- Zone 4 (80-90% MHR): Hard — speed endurance, threshold training
- Zone 5 (90-100% MHR): Maximum — sprinting, VO2max intervals
How to Use Heart Rate Zones
Most endurance training should be in Zones 1-2 (about 80% of your training). This builds your aerobic base efficiently without excessive fatigue. High-intensity training in Zones 4-5 should make up only about 20% of your training — this is the 80/20 principle used by elite athletes.
To monitor your heart rate during exercise, use a chest strap heart rate monitor for the most accuracy, or a wrist-based optical sensor on a smartwatch.
Frequently Asked Questions
How do I find my resting heart rate?
Measure your pulse first thing in the morning before getting out of bed. Count beats for 60 seconds. A normal resting heart rate is 60-100 bpm; fit individuals may be 40-60 bpm.
Is the 220-minus-age formula accurate?
It provides a reasonable estimate for most people but can be off by 10-20 bpm. For more accuracy, consider a graded exercise test or use the Karvonen formula which factors in resting heart rate.
What heart rate zone burns the most fat?
Zone 2 (60-70% MHR) uses the highest percentage of fat for fuel. However, higher-intensity zones burn more total calories, so overall calorie balance matters more for fat loss.