Target Heart Rate Calculator

Determine your optimal heart rate zones for different training goals.
Methodology

This Target Heart Rate Calculator runs instantly in your browser using the formula, inputs, and assumptions explained on this page. Results are educational estimates and should be interpreted alongside personal context.

Methodology Check

Methodology note: The CheckBodyScore Editorial Team last checked the formula, calculation flow, and limitations on 2026-06-18.

Important Disclaimer

Health, pregnancy, dosage, fitness, and finance results are not a substitute for professional medical, clinical, financial, or legal advice.

Your age in years.
Beats per minute (bpm) measured first thing in the morning.
HRR is recommended for better personalization.

Your Heart Rate Metrics

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Estimated Max HR (bpm)
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Heart Rate Reserve (HRR)

Personalized Training Zones

The table shows your target heart rate ranges (bpm) based on your chosen method.

The Science of Heart Rate Training Zones

The Target Heart Rate (THR) Calculator helps you train effectively by defining the intensity of your workout using your heart rate. Your training zone is a percentage of your maximum capacity that correlates with specific physiological goals (e.g., endurance, fat loss, or strength). Training at the correct intensity is key to achieving your fitness objectives efficiently.

This calculator provides zones based on two primary methods, favoring the more personalized Karvonen Formula.

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THR Calculation Logic: The Karvonen Formula

The Karvonen Formula uses the Heart Rate Reserve (HRR)—the difference between your estimated Maximum Heart Rate (Max HR) and your measured Resting Heart Rate (RHR)—to set training zones. This method is more accurate because it accounts for your current fitness level (a lower RHR results in a wider, more accurate training window).

The Karvonen Formula Steps

Step 1: Max HR = 220 − Age
Step 2: HRR = Max HR − RHR

Target HR = (% Intensity × HRR) + RHR

Target Heart Rate Zones and Goals

The five main heart rate zones guide your training:

  1. Zone 1 (50-60% HRR): Very Light, Recovery, Warm-up.
  2. Zone 2 (60-70% HRR): Easy, Fat Burning (great for long duration).
  3. Zone 3 (70-80% HRR): Aerobic, Endurance Training.
  4. Zone 4 (80-90% HRR): Threshold, Anaerobic Capacity.
  5. Zone 5 (90-100% HRR): Maximum Effort, Interval Training.

THR Calculator FAQs

Is the "220 minus Age" Max HR formula accurate?

The standard 220 - Age is an estimate with a wide margin of error (up to 12 bpm). It's best used as a starting point. For superior accuracy, you can use lab testing or sub-maximal stress tests, but for heart rate zone training, it is generally accepted.

Why is the Karvonen formula better than Max HR percentage?

The Karvonen formula is superior because it incorporates your Resting Heart Rate (RHR). A highly-fit person with a low RHR has a larger Heart Rate Reserve (HRR) and thus a higher working heart rate range for the same percentage intensity, making the zones more personalized and challenging.

What is the "Fat Burning Zone"?

The Fat Burning Zone (Zone 2) is typically 60-70% of your HRR. At this low intensity, the body preferentially uses fat as its primary fuel source. While you burn a higher percentage of fat here, you burn more total calories (and thus more total fat) in higher intensity zones.