Heart Rate Zone Calculator
Calculate your personalised heart rate training zones.
Enter your heart rate above to see your training zones.
About heart rate zones
Training zones split your effort range into bands, each targeting a different physiological adaptation. This calculator supports two ways of setting them: a percentage of maximum heart rate, or Friel's lactate threshold heart rate (LTHR) method.
Max HR vs LTHR
The Max HR method sets zones as percentages of your maximum heart rate, which is simple but can be inaccurate if your true max is unknown or estimated. The LTHR method sets zones relative to your lactate threshold heart rate (the heart rate at your threshold effort), which tends to track training-specific fitness more precisely, and is the method used by TrainingPeaks and many endurance coaches.
Using zones in training
Most easy running should sit in Zone 1–2, building aerobic base without excess fatigue. Zone 3 is often called the "grey zone": hard enough to add fatigue but not targeted enough to build much fitness, so many training plans deliberately avoid spending much time there. Zones 4–5 are reserved for threshold and interval work.
Worked example
A 35-year-old with no known max HR can estimate one using the Tanaka formula, 208 − 0.7 × age, giving 208 − 24.5 ≈ 184 bpm. Feeding that into the Max HR method puts Zone 2 (aerobic base) at roughly 110–129 bpm and Zone 4 (threshold) at roughly 147–166 bpm.
Finding your LTHR
The most reliable way to find LTHR is a 30-minute time-trial at maximum sustainable effort: average heart rate over the final 20 minutes is a close approximation of LTHR. If you don't have that data, a recent 10K or half marathon race average heart rate is a reasonable substitute, since both are run close to threshold effort.
Why your watch's zones might differ
GPS watches often set zones from a max heart rate figure calculated from your age out of the box, which can be off by 10–15 bpm for some individuals. If your watch's zones consistently feel too easy or too hard relative to perceived effort, entering a directly measured max HR or LTHR here will usually give more accurate bands than the device default.