Which method is most accurate?

The Karvonen method (using heart rate reserve) is the most personalised as it accounts for your resting HR. A known max HR is more accurate than the 220-age estimate, which can be off by 10-15 bpm.

How do I find my max heart rate?

The most accurate way is a max HR test: warm up for 15 minutes, then run 3 x 3-minute hill repeats at maximum effort. Your highest HR during the final rep is close to your max. The 220-age formula is a rough estimate only.

What zone should most running be in?

For most runners, 80% of weekly mileage should be in Zones 1-2 (easy/aerobic). This builds aerobic base efficiently without excessive fatigue. Quality sessions in Zones 3-5 provide the stimulus for improvement.

RunCalcs

Heart Rate Zone Calculator — HR Training Zones

Calculate heart rate training zones using max HR, age formula, or Karvonen method.

Method

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Max Heart Rate

Rate value for this calculation

How We Calculate This

Heart Rate Zone Methods

Max HR method: Zones = percentages of your maximum heart rate.

220-Age formula: Max HR = 220 - age (rough estimate).

Karvonen method: Target HR = ((Max HR - Resting HR) × %Intensity) + Resting HR. This uses heart rate reserve (HRR) for more accurate zones.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always consult a coach or medical professional for personalised training advice.