Understanding This Calculator
Training zones divide your heart rate range into bands tied to different physiological adaptations — from easy recovery pace up to maximal anaerobic effort. The classic 220-minus-age formula estimates max heart rate; while individual variation exists (±10-12 bpm), it remains the standard starting point for zone-based training.
Zone 2 (60-70% of max) is where most aerobic base-building volume should happen; Zone 5 is reserved for short, high-intensity efforts.
- 220 population-average constant
- age your age in years
- zone % 50-100% band per zone
| Zone | % of Max HR | Purpose |
|---|---|---|
| 1 | 50-60% | Recovery / warm-up |
| 2 | 60-70% | Fat burning / aerobic base |
| 3 | 70-80% | Aerobic / cardio fitness |
| 4 | 80-90% | Lactate threshold |
| 5 | 90-100% | Maximal / anaerobic |
Frequently Asked Questions
How accurate is 220 − age?
It has a standard deviation of roughly ±10-12 bpm across individuals, so it’s a reasonable population estimate but not personally precise. A lab VO2 max test gives a more accurate individual max HR.
Which zone should I train in most?
Most endurance athletes spend 70-80% of training volume in Zone 2, reserving Zones 4-5 for shorter, structured high-intensity sessions.