Heart Rate Zones Calculator
Calculate your maximum heart rate and the five training zones (Zone 1-5) using the Tanaka formula and percent-of-max method.
What is Heart Rate Zones Calculator?
The heart rate zones calculator uses the Tanaka formula (more accurate than the old "220 minus age" rule) to estimate max heart rate, then divides training intensity into five zones used by most modern coaches.
Formula
Max HR = 208 − (0.7 × age) (Tanaka et al., 2001).
Zones as percentage of max:
Zone 1 (Recovery): 50-60%
Zone 2 (Easy/Aerobic): 60-70%
Zone 3 (Tempo): 70-80%
Zone 4 (Threshold): 80-90%
Zone 5 (VO2 max): 90-100%
Worked example
Age 35: max HR = 208 − 24.5 = 183.5 bpm. Zone 2 (easy): 110-128 bpm. Zone 4 (threshold): 147-165 bpm.
How to use this calculator
- Enter your age.
- Optional: resting heart rate (measured first thing in the morning) for HRR calculation.
Frequently asked questions
Why "208 - 0.7×age" instead of "220 - age"?
The 220-age formula is from 1971 and was a quick estimate, not validated research. Tanaka et al. (2001) reviewed 351 studies and found 208 - 0.7×age is more accurate, especially for older adults.
Should I do all my training in Zone 2?
Mostly. Most endurance coaches recommend ~80% of training in Zone 2 (easy aerobic) and 20% harder. This builds aerobic base and reduces injury risk vs constantly running hard.
What's heart rate reserve (HRR)?
The difference between max and resting HR. Lower resting HR = higher HRR = more aerobic capacity headroom. Trained endurance athletes often have resting HR in the 40-50 bpm range.
Does my actual max HR match the formula?
Within ~10 bpm for most people. Test more accurately with a graded exercise test, or look up your peak HR from a hard race effort. Use that as your real max for personalized zones.