Heart Rate Zone Calculator

Calculate your personalized heart rate training zones from your age and resting heart rate. Get all five target zones, from warm-up to maximum effort, using the Karvonen formula with this free tool.

Heart rate measured right after waking up

How to Use

  1. Enter your age

    Input your current age in years.

  2. Enter resting heart rate

    Optionally enter your resting heart rate (bpm) for more accurate Karvonen zones.

  3. View results

    See all 5 heart rate zones with their ranges and training benefits.

What are Heart Rate Zones?

Heart rate zones divide your beats per minute (bpm) during exercise into ranges based on intensity. Even within the same one-hour workout, the physiological response your body experiences differs depending on which zone you train in, so zones let you manage effort by the numbers instead of a vague sense of working 'hard'.

The 5 zones and their benefits

  • Zone 1 Recovery (50–60%): ideal for warm-ups and cool-downs
  • Zone 2 Fat burn (60–70%): low-intensity aerobic work that uses fat as the main fuel
  • Zone 3 Aerobic (70–80%): moderate intensity that builds cardiorespiratory endurance
  • Zone 4 Anaerobic threshold (80–90%): high-intensity intervals near the lactate threshold
  • Zone 5 Maximum (90–100%): very high intensity that stimulates VO2max

This calculator uses the Karvonen method, which also factors in your resting heart rate, so it gives target heart rates tailored to your fitness level rather than a simple percentage calculation.

The Formula

First, estimate your maximum heart rate.

HRmax = 220 − age

The target heart rate for each zone is calculated with the Karvonen formula, which accounts for resting heart rate.

Target HR = ((HRmax − HRrest) × intensity%) + HRrest

  • HRmax: maximum heart rate
  • HRrest: resting heart rate (measured right after waking)
  • intensity%: the exercise intensity for each zone (e.g. Zone 2 is 0.60–0.70)

Example: for a 30-year-old with a resting rate of 60 bpm, HRmax = 220 − 30 = 190. The lower bound of Zone 2 is ((190 − 60) × 0.60) + 60 = 138 bpm and the upper bound is ((190 − 60) × 0.70) + 60 = 151 bpm.

Frequently Asked Questions

What are heart rate zones?
Heart rate zones divide your exercise intensity into 5 ranges relative to your maximum heart rate. Zone 1 (50–60%) is recovery, Zone 2 (60–70%) is fat burning, Zone 3 (70–80%) is aerobic, Zone 4 (80–90%) is the anaerobic threshold, and Zone 5 (90–100%) is the maximum zone. Training in each zone produces a different physiological benefit.
How is maximum heart rate (HRmax) calculated?
The most widely used formula is '220 − age'. For example, a 30-year-old has a maximum heart rate of about 190 bpm. This formula is convenient but can vary by ±10–12 bpm between individuals, so if you need an accurate value, an exercise stress test is recommended.
What is the Karvonen method?
The Karvonen method (heart rate reserve method) finds your target heart rate by factoring in your resting heart rate: THR = ((HRmax − HRrest) × intensity%) + HRrest. It reflects your individual fitness level better than simply using a percentage of maximum heart rate.
Which heart rate zone is best for fat burning?
In Zone 2 (60–70% of maximum heart rate), the proportion of fat used as the primary energy source is highest. However, higher-intensity exercise burns more total calories, so if weight loss is your goal it's effective to combine sustained Zone 2 work with high-intensity sessions.
How do I measure resting heart rate?
The most accurate way is to count your pulse for one minute right after waking, while still lying down before getting up. A typical adult is around 60–80 bpm, while people who do regular aerobic exercise may drop to 50 bpm or below. A lower value generally indicates better cardiovascular efficiency.
Which zone should I train in?
It depends on your goal. For beginners or recovery days, Zone 1–2 works well; to build base fitness and cardiorespiratory endurance, use Zone 3; and to improve performance or speed, Zone 4–5 intervals are appropriate. Many endurance athletes use polarized training, splitting low intensity (Zone 1–2) and high intensity (Zone 4–5) at roughly an 8:2 ratio.
How do I check my heart rate during exercise?
A chest-strap heart rate monitor is the most accurate, while a wrist-based optical smartwatch is sufficient for everyday workouts. Without a device, briefly pause your exercise, count your pulse at the neck or wrist for 15 seconds, and multiply by 4 to estimate your beats per minute.
I'm taking medication — can I trust this calculation as-is?
If you take medications that affect heart rate, such as beta-blockers, or have a heart condition, the target heart rate from the formula may differ from your actual safe range. This calculator is for general reference only, so in such cases be sure to consult a healthcare professional before setting your exercise intensity.
Updated 2026 — WHO standards

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