Heart Rate Zone Calculator
Classic formula. Tanaka (208 − 0.7×age) is more accurate for adults 40+.
Measure before getting out of bed. Lower = better fitness.
Enter your age above to see your zones
Max HR
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Method
% of Max HR
| Zone | BPM | %MHR |
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Understanding Heart Rate Zones
Heart rate zones allow you to train with precision. Instead of guessing effort by feel, your heart rate gives you an objective measure of how hard your cardiovascular system is working. Different zones stress different energy systems, leading to different adaptations in your body.
The 5 Training Zones
Recovery / Easy (50–60% MHR)
Active recovery, warm-up, cool-down. Very low effort — easy conversation.
Aerobic Base / Fat Burn (60–70% MHR)
Builds aerobic base and fat-burning efficiency. Sustainable for long durations.
Aerobic / Cardio (70–80% MHR)
Improves cardiovascular fitness. Moderate effort — can speak in short sentences.
Threshold / Hard (80–90% MHR)
Lactate threshold training. Hard effort — speaking is difficult. Builds speed.
Max / VO₂ Max (90–100% MHR)
Maximum effort. Very short intervals only. Builds peak power and VO₂ max.
Karvonen vs. % of Max HR
The simple method multiplies your max HR by the zone percentage. The Karvonen method is more personalized:
A trained athlete with a resting HR of 45 bpm will get different zone boundaries than a beginner with a resting HR of 75 bpm — even at the same age. Karvonen accounts for this fitness difference.
Frequently Asked Questions
What are heart rate zones?
Heart rate zones are percentage ranges of your maximum heart rate (MHR). Training in different zones produces different physiological adaptations — Zone 2 builds aerobic base and fat-burning efficiency, while Zone 4 pushes your lactate threshold. Most training plans prescribe a mix of zones.
What is max heart rate?
Maximum heart rate (MHR) is the highest heart rate your heart can reach during maximum exertion. The classic formula is 220 − age. The Tanaka formula (208 − 0.7 × age) is considered more accurate for people over 40. These are estimates — a true MHR requires a lab test or all-out effort under supervision.
What is the Karvonen formula?
The Karvonen formula uses Heart Rate Reserve (HRR = Max HR − Resting HR) to calculate target heart rate: Target HR = Resting HR + (HRR × Zone%). This produces more personalized zones than the simple percentage-of-max method because it accounts for your fitness level (resting heart rate).
Which zone is best for fat loss?
Zone 2 (60–70% of MHR) is often called the "fat burning zone" because it relies more heavily on fat as fuel. However, higher-intensity zones burn more total calories. The best approach for fat loss is a combination: mostly Zone 2 for volume plus some higher-intensity work for metabolic benefit.