Heart Rate Zone Calculator

Calculate your 5 heart rate training zones from your max HR or age. Includes Karvonen formula with resting HR.

Heart rate training zones

The 5-zone model is the most widely used system (used by Garmin, Polar, and most coaching programs):

  • Zone 1 (50–60%) — Recovery. Very light effort. Active recovery and warm-up.
  • Zone 2 (60–70%) — Aerobic base. Fat-burning zone. Long, easy endurance runs.
  • Zone 3 (70–80%) — Aerobic. Moderate effort. Improves cardiovascular efficiency.
  • Zone 4 (80–90%) — Threshold. Hard effort. Raises lactate threshold. Tempo and half-marathon pace.
  • Zone 5 (90–100%) — VO₂max. Maximum effort. Short intervals and speed work.

Karvonen formula

The Karvonen formula accounts for your resting heart rate to give more personalised zones: Target HR = HRrest + % × (HRmax − HRrest). Using resting HR makes zones more accurate, especially for trained athletes with a low resting HR.

Finding your true max HR

Age-based formulas are population averages with ±10–12 bpm standard deviation. The most accurate method is a proper field test: warm up thoroughly, then perform 2–3 maximum sprints or a hard hill repeat. Your peak HR in the final effort is your true max.