❤️ Heart Rate Zone Calculator
Find your 5 training heart rate zones
Written by Albert Mateos · Founder & Editor
Last reviewed: May 2, 2026
How it works
Calculate your 5 heart rate training zones based on your age and resting heart rate. Choose between the percentage of max HR method or the more accurate Karvonen formula. Understand which zone burns fat, builds endurance, or improves VO2 max. Optimize your cardio training.
How to Use This Calculator
- Enter your age to calculate maximum heart rate.
- Optionally enter resting heart rate for Karvonen (heart rate reserve) method.
- Review your five training zones with BPM ranges.
- Use the zones to plan cardio sessions based on goal (endurance, lactate threshold, VO2 max).
- Track your heart rate with a chest strap or wrist sensor during training.
Example
Inputs: 35-year-old with resting heart rate of 60 BPM.
Result: Max HR of 185, Zone 2 (60-70%) range of 135-148 BPM.
What it means: Zone 2 workouts at 135-148 BPM build aerobic base and mitochondrial capacity with minimal fatigue cost, making them ideal for 3-5 sessions per week.
Tips
- The 220-age formula has a standard error of +/- 10-12 BPM. Tanaka (208 - 0.7 x age) is more accurate for adults over 40.
- For best accuracy, determine max HR with a field test (hill repeats or max-effort interval) rather than relying solely on formulas.
- Karvonen (heart rate reserve) produces more personalized zones than simple percent-of-max, especially for very fit or deconditioned individuals.
- Chest straps are 2-5 BPM more accurate than wrist-based sensors, especially during interval training and high-intensity work.
- Spend roughly 80% of weekly training time in Zones 1-2 and 20% in Zones 4-5. This polarized model outperforms constant moderate-intensity work.
Learn More
Frequently Asked Questions
- What's the difference between % Max HR and Karvonen?
- The standard % Max HR method is simpler but less personalized. The Karvonen method uses your Heart Rate Reserve (Max HR minus Resting HR), giving more accurate zones that account for your fitness level. If you know your resting HR, Karvonen is better.
- Which zone should I train in?
- It depends on your goals. Zone 2 (60-70%) builds aerobic base and burns fat. Zone 3 (70-80%) improves cardiovascular fitness. Zone 4 (80-90%) increases speed and lactate threshold. Mix zones throughout the week — most athletes spend 80% in Zone 2 and 20% in Zones 4-5.
- How do I measure my resting heart rate?
- Measure first thing in the morning, before getting out of bed. Sit quietly for 1 minute, then count your pulse for 60 seconds. Do this for 3-5 days and take the average. A lower resting HR generally indicates better cardiovascular fitness.
Authoritative resources
We recommend these external sources for further reading from recognized health organizations and peer-reviewed literature:
- Target heart rate zones — American Heart Association
- Exercise intensity and heart rate — Mayo Clinic
Scientific References
This calculator is based on peer-reviewed research and established health guidelines:
- Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. Journal of the American College of Cardiology, 37(1): 153-156. 2001.
- Karvonen MJ, Kentala E, Mustala O. The effects of training on heart rate; a longitudinal study. Annales Medicinae Experimentalis et Biologiae Fenniae, 35(3): 307-315. 1957.