Target Heart Rate Calculator

Find your target heart rate zones for exercise using the Karvonen method, based on your age and resting heart rate.

TARGET HEART RATE
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Max Heart Rate
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Heart Rate Reserve
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Fat Burn Zone
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Cardio Zone
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What Is Target Heart Rate?

Target heart rate (THR) is the ideal heart rate range during exercise that allows you to train at the right intensity for your fitness goals. Training in the correct heart rate zone ensures you are working hard enough to improve cardiovascular fitness without overexerting yourself.

Your maximum heart rate (MHR) is the highest number of beats your heart can safely achieve during exercise. The most common formula estimates MHR as 220 minus your age. Your target heart rate is then calculated as a percentage of this maximum, adjusted for resting heart rate using the Karvonen method for greater accuracy.

Formulas Explained

Max Heart Rate (MHR) = 220 - Age
Karvonen: THR = ((MHR - RHR) × Intensity%) + RHR
Simple: THR = MHR × Intensity%

The Karvonen formula uses Heart Rate Reserve (HRR = MHR - RHR) to provide a more personalized target. It accounts for individual fitness levels since a lower resting heart rate typically indicates better cardiovascular fitness. The simple method is less accurate but requires only your age.

Heart Rate Training Zones

Zone% of MHRPurpose
Zone 1 (Recovery)50-60%Warm-up, active recovery, very light exercise
Zone 2 (Fat Burn)60-70%Base endurance, fat burning, easy conversation pace
Zone 3 (Aerobic)70-80%Cardiovascular fitness, moderate effort
Zone 4 (Threshold)80-90%Lactate threshold, race pace training
Zone 5 (VO2 Max)90-100%Maximum effort, short intervals only

Training Tips

  • Spend 80% of training time in Zones 1-2 for base fitness (polarized training).
  • Use Zone 3 for tempo runs and sustained effort workouts.
  • Reserve Zone 4-5 for interval training, no more than 2 sessions per week.
  • Measure resting heart rate first thing in the morning before getting out of bed.
  • A rising resting heart rate may indicate overtraining or illness.

Frequently Asked Questions

What is a good resting heart rate?

A normal resting heart rate is 60-100 bpm. Athletes often have resting heart rates of 40-60 bpm due to a more efficient cardiovascular system. A lower resting heart rate generally indicates better cardiovascular fitness, though individual variation is normal.

Why use the Karvonen method instead of simple percentage?

The Karvonen method accounts for your fitness level through resting heart rate. Two people of the same age but different fitness levels will get different targets. The simple method ignores individual fitness, making it less accurate for personalized training.

How accurate is the 220-minus-age formula?

The 220-age formula has a standard deviation of about 10-12 bpm, meaning your actual max HR could be 10-12 beats higher or lower. For more accuracy, perform a supervised maximal exercise test. The Tanaka formula (208 - 0.7 x age) may be slightly more accurate for older adults.