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Heart Rate Zone Calculator

Calculate your five heart rate training zones using the Karvonen method. Enter your age and resting heart rate to find the exact beats-per-minute ranges for warm-up, fat burn, cardio, hard training, and maximum effort.

Your age in years. Used to estimate your maximum heart rate.

Your heart rate at complete rest, ideally measured first thing in the morning. Lower resting heart rate generally indicates better cardiovascular fitness.

This heart rate zone calculator uses the Karvonen formula, which accounts for both your maximum heart rate and resting heart rate to produce more personalized training zones than simple percentage-of-max methods. Each zone corresponds to a different training intensity and physiological benefit, helping you train smarter whether your goal is fat loss, endurance, or performance.

How It Works

Karvonen Formula

Target HR = ((Max HR - Resting HR) x Intensity%) + Resting HR

Your target heart rate for each zone equals your heart rate reserve multiplied by the zone intensity percentage, plus your resting heart rate.

Maximum Heart Rate (MHR) = 220 - Age

Heart Rate Reserve (HRR) = MHR - Resting Heart Rate

Target HR = (HRR x Intensity%) + Resting Heart Rate

Zone 1 (Warm Up): 50-60% intensity

Zone 2 (Fat Burn): 60-70% intensity

Zone 3 (Cardio): 70-80% intensity

Zone 4 (Hard): 80-90% intensity

Zone 5 (Maximum): 90-100% intensity

Important Notes:

  • •The Karvonen method uses heart rate reserve (HRR) rather than simple percentage of max, producing more individualized zones
  • •The 220-minus-age formula for max heart rate is an estimate; actual max HR can vary by 10-15 bpm
  • •For the most accurate max heart rate, consider a supervised stress test
  • •Resting heart rate should be measured after waking, before getting out of bed, for 3 consecutive mornings and averaged

Worked Example

A 30-year-old with a resting heart rate of 70 bpm.

Inputs:

  • age:30
  • resting Heart Rate:70

Result:

Max HR is 190 bpm. Heart rate reserve is 120 bpm. Zone 1 (Warm Up): 130-142 bpm, Zone 2 (Fat Burn): 142-154 bpm, Zone 3 (Cardio): 154-166 bpm, Zone 4 (Hard): 166-178 bpm, Zone 5 (Maximum): 178-190 bpm.

Who Is This Calculator For?

  • runners and cyclists
  • gym-goers optimizing workouts
  • people training for fat loss
  • athletes monitoring training intensity

Frequently Asked Questions

The Karvonen method is a heart rate training formula that uses your heart rate reserve (the difference between your maximum and resting heart rates) to calculate personalized training zones. It is more accurate than simply using a percentage of your max heart rate because it accounts for your individual fitness level through resting heart rate.
Measure your resting heart rate first thing in the morning before getting out of bed. Place two fingers on the inside of your wrist or on your neck just below the jaw. Count the beats for 60 seconds, or count for 15 seconds and multiply by 4. Do this for 3 mornings and take the average for the most accurate reading.
Zone 2 (60-70% intensity) is often called the fat burn zone because the highest percentage of calories burned comes from fat at this intensity. However, higher-intensity zones burn more total calories per minute, which can lead to greater overall fat loss. A mix of Zone 2 and Zone 3-4 training is most effective for fat loss.
The 220-minus-age formula is a rough estimate with a standard deviation of about 10-12 bpm. This means your actual max heart rate could be 10-15 bpm higher or lower than the estimate. For precise results, a maximal exercise stress test supervised by a medical professional is recommended.
A common endurance training guideline is the 80/20 rule: spend about 80% of your training time in Zones 1-2 (easy effort) and 20% in Zones 3-5 (moderate to hard effort). For general fitness, focus on Zones 2-3. For performance improvement, add structured intervals in Zones 4-5.
Generally yes. A lower resting heart rate usually indicates better cardiovascular fitness because your heart pumps more blood per beat. Well-trained athletes often have resting heart rates in the 40-60 bpm range. However, some medications and medical conditions also affect resting heart rate, so it is not the sole indicator of fitness.

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Last updated: April 20, 2026