How to use it
- Type your Age in years. The calculator is built for adults aged 18 to 100.
- Under Max heart rate, pick Tanaka: 208 − 0.7 × age, 220 − age, Gulati (women): 206 − 0.88 × age, or I know mine. With I know mine, enter the number in Your max heart rate.
- Optionally add your Resting heart rate. With it, the zones use heart-rate reserve (Karvonen); without it, they are a plain percentage of your max.
- Read Zone 2 at the top and all five zones in the table as they update. Use Copy link, Save image or Share to keep them.
How the calculation works
First the calculator estimates your maximum heart rate. The default is the Tanaka equation, HRmax = 208 − 0.7 × age. Tanaka, Monahan and Seals published it in 2001 from a meta-analysis of 351 studies with 18,712 subjects, then checked it in a lab study of 514 adults aged 18 to 81.
The older 220 − age rule is also offered. The Tanaka paper found that it overestimates max heart rate in young adults, crosses the new line at about age 40, and underestimates it more and more after that. At 40, both give exactly 180 bpm.
The zones run in 10% steps from 50% to 100%. Without a resting rate, each boundary is HRmax × %. With a resting rate, the calculator uses heart-rate reserve, the gap between peak and resting heart rate: target = resting + % × (HRmax − resting). This is the Karvonen method, from his 1957 training study.
| Age | Tanaka: 208 − 0.7 × age | 220 − age |
|---|---|---|
| 25 | 190.5 bpm | 195 bpm |
| 40 | 180 bpm | 180 bpm |
| 60 | 166 bpm | 160 bpm |
How accurate is this?
The zones are exact arithmetic on two numbers, so they are as accurate as your max and resting heart rates. The weak link is the predicted max. Tanaka's equation describes the average of 18,712 people; any one person can sit well above or below that line. The same goes for 220 − age and Gulati.
Gulati and colleagues (2010, Circulation) measured peak heart rate in maximal exercise tests of 5,437 women. The average fitted 206 − 0.88 × age, and the authors concluded that the traditional, male-based calculation overestimates maximum heart rate for age in women. At age 40 it gives 171 bpm, against 180 from Tanaka.
A measured max (from a supervised test) and a resting rate counted on several mornings make the zones much closer to your own.
| Equation | Fitted on | Max at 40 |
|---|---|---|
| Tanaka: 208 − 0.7 × age | 18,712 adults (meta-analysis) | 180 bpm |
| 220 − age | older rule of thumb | 180 bpm |
| Gulati: 206 − 0.88 × age | 5,437 women | 171 bpm |
Max heart rate by age
The three equations side by side, rounded to whole beats. The full chart with Zone 2 for each age is on the max heart rate by age page.
| Age | Tanaka | 220 − age | Gulati (women) |
|---|---|---|---|
| 20 | 194 bpm | 200 bpm | 188 bpm |
| 30 | 187 bpm | 190 bpm | 180 bpm |
| 40 | 180 bpm | 180 bpm | 171 bpm |
| 50 | 173 bpm | 170 bpm | 162 bpm |
| 60 | 166 bpm | 160 bpm | 153 bpm |
| 70 | 159 bpm | 150 bpm | 144 bpm |
Worked example: age 40, resting heart rate 60
Max heart rate is 180 bpm with either formula. The reserve is 180 − 60 = 120 beats. At 70%, the target is 60 + 0.7 × 120 = 144 bpm. Leave the resting rate empty and 70% of max is 126 bpm instead.
| Zone | % of max (no resting rate) | Heart-rate reserve (resting 60) |
|---|---|---|
| 1 · 50–60% | 90–108 bpm | 120–132 bpm |
| 2 · 60–70% | 108–126 bpm | 132–144 bpm |
| 3 · 70–80% | 126–144 bpm | 144–156 bpm |
| 4 · 80–90% | 144–162 bpm | 156–168 bpm |
| 5 · 90–100% | 162–180 bpm | 168–180 bpm |
What Zone 2 means here
"Zone 2" is popular in endurance training plans, but plans don't agree on one definition: some use heart rate, some use lactate or breathing tests. On this page Zone 2 is simply the second 10% band: 60–70% of max, or 60–70% of heart-rate reserve when you add a resting rate. For age 40 and a resting rate of 60, that is 132–144 bpm.
That band sits inside the American Heart Association's moderate range (50–70% of max) when you use % of max, and the CDC's talk test is a simple cross-check: at moderate effort you can talk but not sing.
How the zones compare with published intensity ranges
The American Heart Association puts moderate-intensity activity at about 50–70% of maximum heart rate and vigorous activity at about 70–85%. In the table above, that covers zones 1 and 2 for moderate and zones 3 to the middle of 4 for vigorous.
The CDC describes intensity without a heart rate monitor. Moderate effort is about 5 or 6 on a 0–10 scale, and you can talk but not sing. Vigorous effort starts at 7 or 8, and you can't say more than a few words without pausing for breath.
Karvonen reported improvements in fitness starting at about 60% of heart-rate reserve. That is the lower edge of zone 2 when a resting rate is entered.
Who these formulas were not made for
Age equations describe averages across many people. Your own maximum can sit well above or below the line, which is why I know mine exists for a value measured in a test.
Some medications, such as beta-blockers, and heart conditions change heart rate, and these formulas are not made for that case. The equations are also for adults; under 18, the calculator shows "These formulas are for adults (18+)."
Measuring your resting heart rate
Resting heart rate is your pulse while fully at rest, often taken in the morning before getting up. The American Heart Association says a resting rate between 60 and 100 beats per minute is normal for most adults. A lower resting rate makes the reserve larger, but every zone boundary below the maximum moves down, because each one starts from the resting rate.
Your zones pair well with a target pace. The running pace calculator turns a race time into pace per km or mile.
Questions
- Which max heart rate formula should I pick?
- Tanaka is the default because it was fitted on a large data set and tracks older adults better. 220 − age is offered because many charts use it. If you have a measured max, choose I know mine.
- What heart rate is Zone 2?
- Here, 60–70% of your max heart rate, or 60–70% of heart-rate reserve with a resting rate. It is shown on top of the result. Other plans may define Zone 2 differently.
- Should women use the Gulati formula?
- It is offered because it was fitted on 5,437 women and gives a lower max than 220 − age at every age from 18 to 100. Tanaka found no difference between men and women, so it stays the default. Pick the one you want to compare; a measured max beats all three.
- Why do both formulas give 180 at age 40?
- The two lines cross there. 208 − 0.7 × 40 = 180 and 220 − 40 = 180. Below 40, 220 − age gives the higher number; above 40, Tanaka does.
- What changes when I add a resting heart rate?
- The zones switch from a percentage of max to a percentage of heart-rate reserve (Karvonen). Each zone starts higher, because the resting rate is added back. At age 40 with a resting rate of 60, 70% moves from 126 to 144 bpm.
- Are the zones exact for me?
- No. They are estimates built on a predicted maximum. A measured max and resting rate make them closer to your own numbers.
- Is anything I type sent to a server?
- No. The math runs in your browser. Copy link puts the numbers after a # in the link, a part that browsers don't send to servers.