Estimate your maximum heart rate and the five training zones, from easy recovery to all-out effort, using your age and optionally your resting heart rate.
What are heart rate zones?
Heart rate zones divide exercise intensity into bands based on your maximum heart rate. Training in different zones builds different qualities, from easy aerobic fitness to speed and power.
| Zone | % of max | How it feels |
|---|---|---|
| 1: Recovery | 50–60% | Very easy, warm-ups and cool-downs |
| 2: Easy endurance | 60–70% | Comfortable, can hold a conversation |
| 3: Aerobic | 70–80% | Moderate, talking in short sentences |
| 4: Threshold | 80–90% | Hard, only a few words at a time |
| 5: Maximum | 90–100% | All-out, short bursts only |
Estimating maximum heart rate
Classic: Max HR = 220 − age
Tanaka: Max HR = 208 − 0.7 × age
The Tanaka formula tends to be a little more accurate for older adults. Both are population averages: your real maximum can differ by 10 beats or more.
The Karvonen method
If you enter your resting heart rate, the calculator uses heart rate reserve (max minus resting), which accounts for your fitness:
Target HR = (Max HR − resting HR) × intensity + resting HR
Worked example
At 40, estimated max heart rate is 220 − 40 = 180 bpm. Zone 2 is 108 to 126 bpm. With a resting heart rate of 60, the Karvonen method puts 70% intensity at (180 − 60) × 0.7 + 60 = 144 bpm.
Frequently asked questions
Which zone burns the most fat?
Lower zones burn a higher share of fat, but higher zones burn more calories overall. Total calories and consistency matter most.
How should I split my training?
Many endurance programs keep most training in zones 1 and 2, with a smaller amount of harder work.
Related tools
Estimates for healthy adults. Age-based maximum heart rate formulas can be off by 10 or more beats per minute. Talk to your doctor before starting intense exercise, especially if you take heart medication or have a heart condition.