Heart rate zone calculator.
Four calculation methods × three zone systems: MaxHR, Karvonen HRR, threshold or Breno protocol, paired with Friel 7-zone, Coggan 5-zone or Breno bike/run zones.
Your training zones
Frequently asked
What is the Karvonen formula?
Karvonen uses heart-rate reserve (HRR): Target = ((MaxHR − RestHR) × %intensity) + RestHR. More accurate than %MaxHR because it accounts for individual fitness.
How do I find max HR?
Best: an all-out 5-min field test or graded ramp. Estimate: Tanaka 208 − (0.7 × age) — more accurate than 220 − age.
Which zone system should I use?
Friel's 7 zones for runners using LTHR or HRR. Coggan's 5 zones for cyclists pegged to threshold HR. The Breno protocol is sport-specific (bike vs. run) and built around max HR.
How often should I update zones?
Every 8-12 weeks, after a 5-bpm change in resting HR, or after any clean threshold test.
Zones are the speedometer. The training plan is the engine.
Knowing your HR zones is step one. Step two is a periodized plan that hits the right zone on the right day so the engine actually grows. That's the 1:1 work.
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