HEALTH · HEART RATE ZONES
Heart Rate Zones Calculator
Calculate your 5 training heart rate zones from age-predicted max HR (Fox or Tanaka formula). Shows bpm boundaries and training purpose for each zone.
Zone 1 (Recovery): Very light effort. Active recovery, warm-up, and cool-down.
Zone 2 (Aerobic Base): Light-to-moderate effort. Builds aerobic endurance and fat metabolism.
Zone 3 (Tempo): Moderate-to-hard effort. Improves aerobic capacity and sustained pace.
Zone 4 (Threshold): Hard effort near lactate threshold. Increases race-pace performance.
Zone 5 (Maximal): Maximum effort. Develops VO₂max and anaerobic capacity.
Zone boundaries are estimated from age-predicted max HR (±10–12 bpm). For best accuracy, use a measured max HR from a graded exercise test.
About This Calculator
Training in the right heart rate zone makes every workout more effective. This calculator divides your cardiovascular effort into 5 zones — from easy recovery all the way to maximum output — so you know exactly how hard to push for fat burning, aerobic base, race-pace training, or peak performance.
How It Works
Your maximum heart rate (HRmax) is estimated from your age using either the Fox formula (220 − age) or the Tanaka formula (208 − 0.7 × age). Each of the 5 training zones is then defined as a percentage range of that max: Zone 1 (50–60%), Zone 2 (60–70%), Zone 3 (70–80%), Zone 4 (80–90%), and Zone 5 (90–100%). The bpm boundaries for each zone are calculated by multiplying your HRmax by those percentages. If you have a tested max HR from a lab or graded exercise test, enter it as an override for greater accuracy.
The Formula
HRmax = 220 − age [Fox] HRmax = 208 − 0.7 × age [Tanaka]
- age
- age in years (10–100)
- Zone bpm range
- HRmax × zonePctMin to HRmax × zonePctMax
Frequently Asked Questions
- What is Zone 2 heart rate training?
- Zone 2 (60–70% of max HR) is the aerobic base zone. It trains your body to burn fat efficiently and builds the mitochondrial density that underlies all endurance. Elite athletes spend 70–80% of their training time here. At Zone 2 effort you should be able to hold a conversation.
- How accurate is age-predicted max HR?
- Age-predicted formulas like Fox (220 − age) and Tanaka (208 − 0.7 × age) have a population standard deviation of about ±10–12 bpm. They are useful guides but may over- or under-estimate your actual max HR by more than a zone boundary. A graded exercise test gives the most accurate result.
- What is the difference between this and the Target Heart Rate calculator?
- The Target Heart Rate calculator uses the Karvonen method to find a single target heart rate at a desired intensity, incorporating your resting heart rate. This calculator shows all five zones simultaneously as percentage ranges of your max HR — useful for structuring a full training program.