Heart Rate Calculator
Calculate your maximum heart rate and target heart rate zones for fat burning, cardio, and peak performance.
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How to use this calculator
Heart rate zones are percentages of your maximum heart rate, each targeting different training adaptations.
- 1
Enter your age in years.
- 2
Enter your resting heart rate (measure first thing in the morning before getting up).
- 3
The calculator shows your max heart rate and all five training zones using the Karvonen (Heart Rate Reserve) method.
Frequently asked questions
How do I measure my resting heart rate?
Measure first thing in the morning, before getting out of bed. Place two fingers on your wrist or neck, count beats for 60 seconds. Normal resting HR is 60–100 bpm; athletes often have 40–60 bpm.
What is the best heart rate zone for fat loss?
Zone 2 (60–70% max HR) burns the highest percentage of calories from fat. However, higher zones burn more total calories. Both are effective for fat loss — Zone 2 is sustainable for longer sessions.
Is the 220−age formula accurate?
It is a population average with a standard deviation of ±10–12 bpm. Individual max HR can vary significantly. The Tanaka formula (208 − 0.7 × age) is slightly more accurate for older adults. The only precise measurement is a maximal exercise test.
What is the Karvonen method?
The Karvonen (Heart Rate Reserve) method accounts for your fitness level by using the reserve between resting and max HR. It gives more personalised training zones than using max HR percentages alone.
Heart rate zones for training
The five heart rate zones
Zone 1 (50–60%): recovery and warm-up. Zone 2 (60–70%): aerobic base, fat burning, can sustain for hours. Zone 3 (70–80%): aerobic conditioning, "comfortably hard." Zone 4 (80–90%): lactate threshold training, hard effort. Zone 5 (90–100%): maximum effort, anaerobic, sustainable only in short bursts.
Why Zone 2 training is popular
Zone 2 training builds mitochondrial density and aerobic capacity with minimal recovery cost. It forms the base of most endurance athletes' training — typically 80% of total volume. It can be sustained for long periods, making it ideal for building an aerobic base without burnout.
Heart rate variability (HRV)
Beyond average heart rate, HRV measures variation between heartbeats. Higher HRV indicates better cardiovascular fitness and recovery capacity. Low HRV after hard training signals the need for rest. HRV tracking (via smartwatch or chest strap) is increasingly used by athletes to guide training intensity.
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →