Beatcast
Heart rate zones calculator
Updated
What this does
Enter your age, and optionally a measured maximum, a resting heart rate or a threshold heart rate. Choose a method and a number of zones. You get a table of ranges in beats per minute. Everything runs in your browser. Nothing you type is sent, stored or logged.
The calculator
Whole years, 10 to 100.
How the zones are worked out.
Five is Beatcast's default.
Optional, 100 to 230 bpm. Left empty, the Tanaka estimate from your age is used.
Optional, 30 to 120 bpm. The Karvonen method needs it.
Optional, 80 to 220 bpm. Percent of threshold needs it.
How the numbers are built
The page follows the same rules as Beatcast, so the same inputs give the same beats per minute in both.
Maximum heart rate. If you enter a measured maximum, it is used. Otherwise the page estimates one with the Tanaka equation: 208 minus 0.7 times your age, rounded. Tanaka, Monahan and Seals published it in 2001 in the Journal of the American College of Cardiology.
Percent of maximum (the default). Each zone starts at a share of your maximum. Five zones start at 50, 60, 70, 80 and 90 percent. Three zones start at 60, 70 and 85. Two start at 60 and 85.
Karvonen, or heart rate reserve. The same shares applied to the gap between resting and maximum, then added to your resting rate: resting plus (maximum minus resting) times the share. It needs a resting heart rate below your maximum. Karvonen and colleagues described it in 1957.
Percent of threshold. If you know your lactate threshold heart rate, each zone starts at a share of it. Five zones start at 65, 85, 90, 95 and 100 percent. Three start at 65, 88 and 100. Two start at 65 and 100. The five-zone set approximates Friel's running zones.
A zone starts at its lower number and runs up to, but not including, the lower number of the next one. The top zone has no upper limit.
Names
Five zones: Recovery, Endurance, Tempo, Threshold, Max. Three: Easy, Steady, Hard. Two: Easy, Hard. In Beatcast you can rename any of them.
A worked example
Age 40, no measured maximum, percent of maximum, five zones. Tanaka gives 208 minus 28, which is 180.
| Zone | Name | Range (bpm) | Share of maximum |
|---|---|---|---|
| 1 | Recovery | 90 to 107 | 50 to 60% |
| 2 | Endurance | 108 to 125 | 60 to 70% |
| 3 | Tempo | 126 to 143 | 70 to 80% |
| 4 | Threshold | 144 to 161 | 80 to 90% |
| 5 | Max | 162 and up | 90% and up |
The same person with a resting rate of 60 and Karvonen: reserve 120, so zone 2 starts at 60 plus 72, which is 132, and runs to 143.
With a threshold of 160 and five zones by threshold, the lower bounds are 104, 136, 144, 152 and 160.
Zone 2 gets its own page, with four definitions side by side: the zone 2 calculator.
How good is an estimate
An age-based maximum misses any one person by roughly 10 to 12 beats either way. Nes and colleagues reported a standard error of 10.8 beats per minute for their equation in 2013. A measured maximum, or a threshold from a test, is better than any formula. If you do not have one, treat the table as a starting line and adjust it as you learn how your own numbers feel.
These are training estimates. If you take medication that changes your heart rate or have a heart condition, ask your clinician before using age-based numbers. Beatcast is not a medical device.
Beatcast uses these same numbers
Onboarding asks for your age and builds zones from it. The sensor screen shows which numbers produced them. During a session the whole screen takes the colour of your current zone, and the number stays on the Lock Screen and in the Dynamic Island while you use other apps. You can rename the zones, set the boundaries by hand, and keep a separate zone profile for winding down.
There is no way to hand a result from this page to the app. You enter the numbers in the app, and they match.
Beatcast on the App Store. Fourteen days free, then one purchase.
Questions
Which method should I use?
Percent of maximum is the simplest. Karvonen suits you if you know your resting rate. Threshold suits you if you have had a test.
Why do two sites give different zones?
Different formulas, different maximums, different edges. Beatcast says which it used.
How many zones?
Five is the common default. Two or three are enough if you want a single line to hold or stay under.
Related
See also: Karvonen calculator, zones by age, zones explained, calories burned by heart rate.
Good to know
Beatcast is not a medical device. It is built for training and general wellbeing, and it cannot detect, diagnose, treat or monitor any condition. If something about your heart worries you, talk to a doctor rather than to an app.
The Bluetooth word mark is a registered trademark of Bluetooth SIG, Inc. Apple, iPhone, iPad, Apple Watch, AirPods, Apple Health, Dynamic Island, Lock Screen and StandBy are trademarks of Apple Inc. Powerbeats and Beats are trademarks of Beats Electronics, LLC. All other device and app names belong to their owners and are used only to say which sensors Beatcast can read. Beatcast is an independent product and is not affiliated with, endorsed by or certified by any of them.
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