Heart Rate Zone Calculator

It uses the common 220 − age formula. Real maximum heart rates vary, and other formulas (Tanaka, Gellish) exist, so treat the number as a population estimate rather than a personal cap.

The five-zone model is widely used in endurance training: 50–60% recovery, 60–70% endurance, 70–80% aerobic, 80–90% anaerobic, and 90–100% maximum. Each zone targets a different training adaptation.

Zone 5 (90–100%) is the most demanding zone and is usually limited to short intervals. If you have a medical condition, talk to a clinician before pushing into anaerobic territory.