Heart rate zones are bands of your maximum heart rate, each with a training purpose: easy endurance, aerobic fitness, threshold work, short all-out efforts. The calculator estimates your maximum with the formula you choose, then gives the five zones in beats per minute. If you enter your resting heart rate, it uses the Karvonen method, which fits fitter people better.
Example: you are 40. Tanaka: 208 − 0.7 × 40 = 180 bpm. Zone 2 (60–70%) is 108–126 bpm. With a resting pulse of 60, Karvonen moves zone 2 up to 132–144 bpm, because it counts only the range above your resting rate.
Maximum heart rate by age
| Age | Tanaka (208 − 0.7 × age) | Classic (220 − age) | Gulati, women (206 − 0.88 × age) |
|---|---|---|---|
| 20 | 194 | 200 | 188 |
| 30 | 187 | 190 | 180 |
| 40 | 180 | 180 | 171 |
| 50 | 173 | 170 | 162 |
| 60 | 166 | 160 | 153 |
| 70 | 159 | 150 | 144 |
Tanaka’s formula came from a meta-analysis of 351 studies and a lab study, which found that 220 − age overestimates the maximum in young adults and underestimates it from middle age. Gulati’s formula came from exercise tests of more than 5,000 women.
The five zones
For a 40-year-old with a maximum of 180 bpm:
| Zone | % of max | Simple method | Karvonen, resting 60 | What it is for |
|---|---|---|---|---|
| 1 – very easy | 50–60% | 90–108 bpm | 120–132 bpm | warm-up, recovery, walking |
| 2 – easy | 60–70% | 108–126 bpm | 132–144 bpm | long endurance; you can talk in full sentences |
| 3 – moderate | 70–80% | 126–144 bpm | 144–156 bpm | aerobic fitness; talking gets harder |
| 4 – hard | 80–90% | 144–162 bpm | 156–168 bpm | threshold; a few words at a time |
| 5 – maximum | 90–100% | 162–180 bpm | 168–180 bpm | short intervals, sprints |
Sports watches use similar five-zone systems, though some set them from a lactate threshold instead of the maximum; the idea is the same.
Measuring your resting heart rate
Take it in the morning, before getting up: count the beats for 30 seconds at the wrist or neck and double it, on three mornings, and use the average. Many adults are between 60 and 100 bpm; trained endurance athletes can be in the 40s. A resting pulse that rises by several beats over a few days can be a sign of illness, overtraining or poor sleep.
Safety
Medicines such as beta blockers lower the heart rate, so zones from a formula do not apply. If you have heart disease, high blood pressure, chest pain or dizziness when exercising, or you are starting hard training after a long break, talk to your doctor first. For pace targets, the running pace calculator works out splits; for energy, the calories burned calculator.
Once zet4u is saved on your phone, the calculator works offline – at the gym or on a trail with no signal.
Frequently asked questions
How do I calculate my maximum heart rate?
The most used formula today is Tanaka's: 208 − 0.7 × age. At 40 that gives 180 beats per minute. The older 220 − age gives the same at 40 but too much for young people and too little for older ones. For women, Gulati's 206 − 0.88 × age fits better: 171 at 40.
What heart rate zone burns the most fat?
Zone 2 (60–70% of the maximum) uses the largest share of fat for fuel, and you can keep it up for a long time. But harder zones burn more calories per minute in total. For weight, the total energy you use over the week matters more than the zone.
What is the Karvonen method?
A way to set zones from your heart-rate reserve – the gap between your resting and maximum pulse – instead of from the maximum alone: target = resting + (max − resting) × %. With a maximum of 180 and a resting pulse of 60, 70% is 60 + 120 × 0.7 = 144 bpm, against 126 bpm by the simple method.
How accurate are max heart rate formulas?
For an individual, not very: real maximums scatter about 10 beats either side of any formula's line. A supervised exercise test measures yours. A hard race or an all-out effort uphill gives a rough idea, if your doctor agrees it is safe for you.
Sources
- Tanaka H., Monahan K.D., Seals D.R.: Age-predicted maximal heart rate revisited, Journal of the American College of Cardiology 37 (2001) 153–156
- Gulati M. et al.: Heart rate response to exercise stress testing in asymptomatic women, Circulation 122 (2010) 130–137
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