Heart Rate Zone Calculator
Calculate your 5 heart rate training zones (recovery, endurance, aerobic, threshold, maximum) from your age or known maximum heart rate. Everything is calculated locally—no health data is sent to a server.
How it works
Training in the right heart rate zone lets you target a specific goal: burning fat, building endurance, or improving max speed. This tool calculates the five classic training zones from your estimated or measured maximum heart rate.
Why use the Tanaka formula instead of “220 – age”?
The historical “220 minus age” formula is simple but imprecise, especially after age 40. The Tanaka formula (208 – 0.7 × age), based on a meta-analysis of thousands of people, is now considered more reliable on average. However, it remains an estimate: a real lab measurement or stress test is always more accurate.
What is resting heart rate used for?
By entering your resting HR, the tool uses the Karvonen method, which calculates zones based on your “heart rate reserve” (the difference between max HR and resting HR) rather than a simple percentage of max HR. This method is generally considered more personalized because it takes your baseline fitness into account.
These health details stay strictly local: nothing is sent or stored on a server.