Zone 2 Heart Rate Calculator

Calculate your Zone 2 heart rate training range using Karvonen (HRR), percentage of max HR, or MAF methods. Find your optimal aerobic training zone.

years
bpm
bpm

Estimated: 220 - age = 185 bpm

Uses Heart Rate Reserve (HRR) for more personalized zones based on your resting heart rate.

All Heart Rate Training Zones

ZoneNameHeart Rate% of HRR

These zones are estimates. For the most accurate heart rate zones, consider a lab-based lactate threshold test or VO2 max assessment.

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About the Zone 2 Heart Rate Calculator

Learn more about the calculator and its creator

Jonas

Jonas

I have been a multi-sport athlete for over 10 years and I built this calculator to help athletes like you and me.

How the Zone 2 Heart Rate Calculator Works

This calculator determines your Zone 2 heart rate training range using three proven methods: Karvonen (Heart Rate Reserve), percentage of maximum heart rate, or the MAF (Maffetone) method. Zone 2 is your optimal aerobic training zone for building endurance and improving fat oxidation.

Calculation Methods

  • Karvonen (HRR): Zone 2 = Resting HR + (Max HR - Resting HR) × 60-70%
  • Percentage: Zone 2 = Max HR × 60-70%
  • MAF: Upper limit = 180 - Age (Zone 2 is 10 bpm below this)

What is Zone 2 Training?

Zone 2 training is low-intensity aerobic exercise performed at a heart rate where you can maintain a conversation. It's the foundation of endurance training, building mitochondrial density, improving fat oxidation, and enhancing cardiovascular efficiency without accumulating excessive fatigue.

Elite endurance athletes spend approximately 80% of their training time in Zone 2, using the remaining 20% for high-intensity work. This polarized approach maximizes aerobic development while allowing adequate recovery between hard sessions.

Benefits of Zone 2 Training

  • Builds aerobic base and mitochondrial density
  • Improves fat oxidation and metabolic efficiency
  • Enhances recovery between hard training sessions
  • Reduces injury risk compared to high-intensity training
  • Sustainable for longer duration sessions
  • Establishes foundation for faster race performances

Frequently Asked Questions

What is Zone 2 training?

Zone 2 training is low-intensity aerobic exercise where you can maintain a conversation. It builds your aerobic base, improves fat oxidation, and enhances mitochondrial function - the foundation for all endurance performance.

What is my Zone 2 heart rate?

Your Zone 2 heart rate is typically 60-70% of your heart rate reserve (Karvonen method) or 60-70% of your max heart rate. For a 35-year-old with resting HR of 60 and max HR of 185, Zone 2 would be approximately 135-148 bpm using Karvonen.

How do I calculate my Zone 2 heart rate?

Using the Karvonen method: Zone 2 = Resting HR + (Max HR - Resting HR) × 60-70%. For the MAF method, simply use 180 minus your age as your upper limit.

What is Zone 2 cardio?

Zone 2 cardio is any aerobic activity performed at a low enough intensity to stay in the Zone 2 heart rate range - typically running, cycling, swimming, or walking. You should be able to hold a conversation.

Does Zone 2 burn fat?

Yes, Zone 2 training maximizes fat oxidation. At this intensity, your body primarily uses fat for fuel rather than carbohydrates, making it excellent for improving metabolic health and body composition.

What is considered Zone 2 cardio?

Zone 2 cardio is exercise performed at 60-70% of your max HR or heart rate reserve. Activities include easy running, cycling, swimming, brisk walking, or any exercise where you can maintain a conversation.

Is Zone 2 training a waste of time?

No - Zone 2 training is essential for building aerobic capacity, improving fat metabolism, and recovery. Elite endurance athletes spend 80% of their training time in Zone 2. It's the foundation for sustainable performance gains.

What is the difference between Karvonen and percentage methods?

The Karvonen method uses heart rate reserve (max HR - resting HR) for more personalized zones. The percentage method simply uses a percentage of max HR. Karvonen is more accurate for trained athletes with lower resting heart rates.

What is the MAF method?

The MAF (Maffetone) method uses a simple formula: 180 minus your age as your maximum aerobic heart rate. It's designed to keep you in the aerobic zone for building endurance base.

How long should Zone 2 runs be?

Zone 2 runs should typically be 45-90 minutes for most runners. Longer durations (up to 2-3 hours) are beneficial for marathon training. The key is staying in the zone - slow down if your heart rate rises.

The Science Behind This Calculator

Learn about the researchers whose work powers this tool

MJ
Physiology

Finnish physiology researcher (1918-2009) who created the Karvonen Formula: Target HR = HRrest + %Intensity × (HRmax - HRrest). This uses Heart Rate Reserve (HRR) as the intensity anchor, demonstrating that HRR correlates more tightly with VO₂ reserve than simple %HRmax.

Key Achievements

  • Creator of the Karvonen Formula (HRR method)
  • Pioneered Heart Rate Reserve calculations
  • Demonstrated HRR-VO₂ reserve correlation

+2 more achievements

PM
Sports Medicine & Holistic Endurance Training

Sports medicine physician who developed the MAF Method (Maximum Aerobic Function), known for the 180-age heart-rate formula to target aerobic (fat-oxidation) zones. Emphasizes low-stress, injury-reducing training with focus on metabolic health.

Key Achievements

  • Creator of the MAF Method (180-Age formula)
  • Coached 6-time Ironman World Champion Mark Allen
  • Pioneer of low heart rate training

+2 more achievements