Heart rate
Max Heart Rate Calculator
Use this when your watch zones feel wrong or you have a high-effort reading and want a better working max heart-rate input.
- Uses the 208 - 0.7 x age estimate.
- Lets you compare an observed hard-effort value.
- Shows zones from the working max so you can judge the impact.
Max heart rate is the anchor for many watch zones, so a poor estimate can make every training range misleading.
- Enter age for a conservative starting estimate.
- Use an observed value only when it came from a healthy, rested, genuinely hard effort with a believable sensor trace.
- A maximal field test is optional: avoid it when new to exercise, ill, injured, unusually fatigued, symptomatic, or medically restricted.
Use the highest reliable value as a working max, not a fitness score or permanent truth. Pace is external output; heart rate is internal cost, so heat, hills, stress, and fatigue can change the relationship.
- Prefer reliable race or hard-session history before scheduling a dedicated maximal test.
- If testing is appropriate, warm up thoroughly, use a safe hill or treadmill, build through repeated hard efforts, and confirm the highest stable reading rather than a spike.
- Update the working max when later evidence is higher and believable, then validate the resulting zones with easy-run breathing and recovery.
Use the working max in the full heart-rate zone calculator, then compare zones with pace, breathing, perceived effort, and recovery across several runs.
Heart-rate calculators Heart-Rate Zone Calculator Estimate easy, steady, and hard running zones. Heart-Rate Drift Calculator Estimate aerobic decoupling from a steady run. Max Heart Rate Calculator Compare age estimates with observed hard-effort readings. Heart Rate Reserve Calculator Use resting and max heart rate for personalized ranges. LTHR Zone Calculator Calculate zones from lactate threshold heart rate.