Heart Rate Zone Calculator
Find your 5 personalised training zones for fat burn, cardio endurance, and peak performance — based on your age and resting heart rate.
Understanding heart rate training zones
Training in specific heart rate zones allows you to target different physiological adaptations — from improving fat metabolism to building cardiovascular endurance to developing peak speed and power. Most endurance training programs use a 5-zone model.
The 5 zones explained
- Zone 1 – Recovery (50–60%): Very light effort. Active recovery, warm-ups, cool-downs. Promotes blood flow and muscle repair without adding fatigue.
- Zone 2 – Aerobic base (60–70%): The "fat burning zone." Conversational pace. Builds aerobic base and fat-oxidation efficiency. Most endurance training should happen here.
- Zone 3 – Aerobic (70–80%): Moderate effort. Improves aerobic capacity and muscular endurance. Sustainable for 30–60 minutes.
- Zone 4 – Threshold (80–90%): Hard effort. Raises lactate threshold — your ability to sustain high intensity. Interval training and tempo runs live here.
- Zone 5 – VO2 Max (90–100%): Maximum effort. Short bursts only. Develops VO2 max and neuromuscular power. Unsustainable for more than a few minutes.
Karvonen vs. % of Max HR
The Karvonen method uses Heart Rate Reserve (HRR = Max HR − Resting HR) to calculate zones. Because it accounts for your resting heart rate, it's more individualised and generally considered more accurate, especially for fit individuals with a low resting HR.
The % of Max HR method is simpler — it just takes percentages of your maximum heart rate directly. It's less personalised but still useful if you don't know your resting HR.
How to measure your resting heart rate
Measure first thing in the morning before getting out of bed. Count your pulse for 60 seconds (or 30 seconds × 2). A typical resting HR is 60–80 bpm; well-trained athletes often see 40–55 bpm. Wearables like Garmin or Whoop can track this automatically overnight.