Calculator
Heart rate zone calculator
Your estimated maximum heart rate and five training zones in beats per minute, with zone 2 highlighted. Add your resting heart rate for a more personal version.
Fill in the fields and press Calculate to see your estimate.
Estimates only, worked out in your browser. Nothing you enter is sent or stored.
Zone 2 is 60–70% of your maximum heart rate, and the best simple estimate of maximum heart rate is 208 − 0.7 × your age. For a 45-year-old that’s a maximum of about 177 beats per minute and a zone 2 of roughly 106 to 124. The calculator above works out all five zones for your age, and if you add your resting heart rate it gives a more personal version using your heart rate reserve.
The formulas
Maximum heart rate. The calculator uses the Tanaka equation: HRmax = 208 − 0.7 × age. It came from a meta-analysis of 351 studies and over 18,000 people, then was checked in a lab with 514 healthy adults. The authors found the old 220 − age formula underestimates maximum heart rate in older adults, and that age predicts it largely regardless of sex or fitness.
Zones by percentage of maximum. A common five-zone scheme, as set out by the heart-rate monitor maker Polar:
| Zone | Feel | % of max |
|---|---|---|
| 1 | Very light | 50–60% |
| 2 | Light, conversational | 60–70% |
| 3 | Moderate | 70–80% |
| 4 | Hard | 80–90% |
| 5 | Maximum | 90–100% |
Zones from heart rate reserve (optional). If you enter a resting heart rate, the calculator uses the Karvonen method: target = resting + percentage × (max − resting). This builds your own resting heart rate into every zone, and shifts them all upward.
A worked example
A 45-year-old with a resting heart rate of 60:
| Age only | With resting heart rate 60 | |
|---|---|---|
| Maximum | 208 − 31.5 = 177 | 177 |
| Zone 2 low (60%) | 0.60 × 176.5 = 106 | 60 + 0.60 × 116.5 = 130 |
| Zone 2 high (70%) | 0.70 × 176.5 = 124 | 60 + 0.70 × 116.5 = 142 |
The two versions differ by almost 20 beats. That’s normal: they’re different methods. The age-only version is a cautious starting point; the reserve version usually suits men who already do some cardio.
How to use your zones
- Check it against the talk test. In zone 2 you can speak in full sentences but wouldn’t want to sing. If the number says zone 2 and you can’t talk, trust your breathing and slow down.
- Build volume in zones 1–2 first. Brisk walking, easy cycling along the Martin Goodman Trail or the rowing machine all count. CSEP’s movement guidelines recommend at least 150 minutes of moderate to vigorous aerobic activity a week for adults.
- Add harder work sparingly. Zones 4–5 are for short intervals once you have a base.
How much of your week to spend in each zone is covered in zone 2 training for men over 40 and how much cardio a man over 40 should do.
Limitations
Any age formula predicts the average for your age. Your real maximum may be well above or below it, which shifts every zone. Only a supervised maximal test measures it directly. Day-to-day conditions matter too: on a hot, humid July afternoon you may find zone 2 comes at a slower pace than in October.
When to see a doctor
Some medications, especially beta blockers, lower your heart rate during exercise, which makes these zones misleading. See your doctor before training by heart rate if you take heart or blood-pressure medication, have a known heart condition, or get chest pain, dizziness or unusual breathlessness when you exercise.
Next step
Zones make easy days easy and hard days count. If you want cardio fitted around your strength training and your calendar, that planning is part of monthly 1:1 coaching.
Questions people also ask
What is zone 2 heart rate for a 45-year-old man?
About 106 to 124 beats per minute, using 60–70% of an estimated maximum of 177. If you add a resting heart rate of 60, the heart-rate-reserve version moves it up to about 130 to 142.
Should I use 220 minus age or 208 minus 0.7 times age?
Tanaka's 208 − 0.7 × age was built from far more people, including older adults, and found 220 − age underestimates maximum heart rate as you get older. The gap is small at 40 and grows after 50.
Why does zone 2 feel so slow?
Because it's meant to be easy: you should be able to talk in full sentences. If you're new to it, you may need to walk the uphill sections or slow right down at first.
Is my watch's heart rate accurate enough?
For steady zone 2 work it's usually close enough. If the reading ever disagrees with how you feel, trust the talk test over the screen.