Calculator
Heart Rate Zone Calculator
Quick answer
Pick a max-heart-rate equation. Tanaka, 2001, is 208 − 0.7 × age, from a meta-analysis and a lab check. The traditional alternative is 220 − age, which tends to sit low for older adults.
Zones are 10-point bands from 50% to 100% of that max. Karvonen uses the same percents of heart-rate reserve: (max − resting) × percent + resting.
Need a 1RM first? Use the one rep max calculator →
Estimates only. Testing a true max carries risk; use a spotter or safety arms. Not medical advice.
Estimated max: 184 bpm. These bands are a coaching convention, not a diagnosis.
| Zone | % max | bpm | Karvonen bpm |
|---|---|---|---|
| 1 | 50–60% | 92–110 | 122–134 |
| 2 | 60–70% | 110–128 | 134–146 |
| 3 | 70–80% | 128–147 | 146–159 |
| 4 | 80–90% | 147–165 | 159–171 |
| 5 | 90–100% | 165–184 | 171–184 |
On this page
How does the heart rate zone calculator work?
Max heart rate is estimated, not measured. Tanaka's equation came out of 351 studies and was checked in 514 adults. The lab regression was 209 − 0.7 × age, close to the meta-analysis figure of 208 − 0.7 × age. This page uses 208 − 0.7 × age.
220 − age is the number everyone remembers. It is a rough rule. Tanaka's paper argued that it underestimates max heart rate in older adults. If you have a measured max from a real test, use that and ignore both equations.
What inputs does it need?
Age, a resting heart rate if you want Karvonen zones, and a choice of equation. Resting heart rate is best taken in the morning, not after coffee and a flight of stairs.
The five bands are a coaching convention. They are not a diagnosis and they are not a claim that 70% is a fat-burning switch.
Worked example with sample numbers
Example only: age 35. Tanaka gives 208 − 24.5 = 183.5 bpm. 220 − 35 = 185. At this age they nearly agree. At 60 they do not: Tanaka gives 166, and 220 − age gives 160.
With a resting heart rate of 60 and a max of 184, Karvonen at 70% is (184 − 60) × 0.70 + 60 = about 147. Percent of max at 70% is about 129. The Karvonen number is higher because it starts from rest instead of from zero.
Common mistakes
Holding a conversation-pace run up to a calculated max and calling the watch wrong. The equation is an average. Your max can sit well off it.
Using zones to replace a medical stress test. This page is not that. The zones guide says the same thing in longer form.
FAQ
Which max heart rate formula is better?
Tanaka's 208 − 0.7 × age has a published evidence trail. 220 − age is the traditional estimate and is still widely used. A measured max beats both.
What is the Karvonen formula?
Target heart rate = (max − resting) × intensity + resting. It is heart-rate reserve, described by Karvonen, Kentala, and Mustala in 1957.
Are these the official zone names?
No. The page labels them 1 through 5 by percent. Names like 'fat burn' are marketing.
Do lifters need heart-rate zones?
Only if you also do conditioning and want a cap or a floor. A heavy set of five will spike heart rate without living in zone 2.
Can medication change this?
Yes. Some drugs lower heart rate. The equations do not know your prescription. Ask a clinician if that applies to you.