Target Heart Rate Calculator

Find your 5-zone heart rate training ranges for fat burn, aerobic fitness, and peak performance.

Heart Rate Training Zones

Training at specific heart rate zones produces targeted physiological adaptations. Use zones to plan workouts — Zone 2 for fat burning and endurance base, Zone 4 for performance, Zone 5 for peak efforts.

Accuracy The Karvonen formula is more accurate than simple percentage-of-max methods, but estimated max HR (Tanaka formula) carries ±7 bpm variation. Your true zones may shift slightly — use perceived exertion alongside heart rate for the best results.

Karvonen Formula

HRR = Max HR − Resting HR
Zone target = Resting HR + (HRR × percentage)
Max HR calculated with Tanaka: 208 − 0.7 × age

What to do with your result
  • Use your Zone 2 range for all easy and long-distance runs — this builds aerobic base and burns fat efficiently.
  • Schedule 1–2 Zone 4 interval sessions per week to raise your anaerobic threshold and improve race pace.
  • Wear a heart rate monitor during workouts and stay within the target zone for at least 80% of your session time.
  • Re-calculate every 3 months as your resting HR decreases with improved fitness, which shifts all zones slightly.

Frequently Asked Questions

What is the Karvonen formula for target heart rate?
The Karvonen formula calculates target heart rate using your Heart Rate Reserve (HRR): Target HR = Resting HR + (HRR × intensity%). HRR = Max HR − Resting HR. This produces more personalized zones than simple percentage of max HR because it accounts for your individual fitness level.
How do I find my resting heart rate?
Measure your resting heart rate first thing in the morning before getting out of bed. Count your pulse for 60 seconds (or 30 seconds and double it). Do this for 3 consecutive days and average the results for accuracy. A normal resting HR is 60–100 bpm; well-trained athletes may be 40–60 bpm.
Which training zone is best for fat burning?
Zone 2 (60–70% of HRR) is commonly called the 'fat burning zone' because fat provides the largest proportion of fuel at this intensity. However, higher-intensity zones burn more total calories per minute. For overall fat loss, a mix of Zone 2 endurance work and higher-intensity intervals is most effective.
How accurate is the Tanaka formula for max heart rate?
The Tanaka formula (208 − 0.7 × age) is more accurate than the older 220 − age formula, with a standard error of about ±7 bpm. True max HR varies significantly between individuals — the only way to know your exact max HR is through a graded exercise test supervised by a professional.
How often should I train in each heart rate zone?
A well-rounded training plan typically follows the 80/20 rule: about 80% of training time in Zone 1–2 (easy, aerobic) and 20% in Zone 3–5 (moderate to high intensity). Zone 2 builds your aerobic base and promotes recovery, while Zone 4–5 intervals improve speed and VO2 max.
This calculator is for educational purposes only. Consult a qualified healthcare professional for medical advice.