Calculate Your Target Heart Rate.

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Target Heart Rate Calculator

Optimize your workout by calculating your ideal heart rate zones based on the Karvonen Formula.

Your Personalized Results:

Maximum Heart Rate (MHR): BPM

Heart Rate Reserve (HRR): BPM

Fat Burning Zone (50% – 60%)
Aerobic / Fitness (70% – 80%)
Vigorous / Anaerobic (85%+)
function calculateTargetHeartRate() { var age = document.getElementById('thr_age').value; var rhr = document.getElementById('thr_rhr').value; var resDiv = document.getElementById('thr_results'); if (age === "" || rhr === "" || age <= 0 || rhr <= 0) { alert("Please enter valid positive numbers for Age and Resting Heart Rate."); return; } var ageNum = parseFloat(age); var rhrNum = parseFloat(rhr); // Standard Max Heart Rate formula var mhr = 220 – ageNum; // Heart Rate Reserve (Karvonen) var hrr = mhr – rhrNum; if (hrr <= 0) { alert("Resting heart rate cannot be higher than maximum heart rate. Please check your inputs."); return; } // Calculations var fatMin = Math.round((hrr * 0.50) + rhrNum); var fatMax = Math.round((hrr * 0.60) + rhrNum); var aeroMin = Math.round((hrr * 0.70) + rhrNum); var aeroMax = Math.round((hrr * 0.80) + rhrNum); var vigMin = Math.round((hrr * 0.85) + rhrNum); document.getElementById('mhr_val').innerText = mhr; document.getElementById('hrr_val').innerText = hrr; document.getElementById('zone1').innerText = fatMin + " – " + fatMax + " BPM"; document.getElementById('zone2').innerText = aeroMin + " – " + aeroMax + " BPM"; document.getElementById('zone3').innerText = vigMin + "+ BPM"; resDiv.style.display = 'block'; }

How to Understand Your Target Heart Rate

Training at the right intensity is the difference between seeing rapid results and hitting a plateau. Your Target Heart Rate (THR) is a range of beats per minute (BPM) that allows your heart and lungs to receive a maximal benefit from a workout.

The Karvonen Formula Explained

While basic calculators simply take 220 minus your age, our calculator uses the more accurate Karvonen Formula. This method factors in your Resting Heart Rate (RHR), which is a key indicator of your current cardiovascular fitness level. By calculating your Heart Rate Reserve (HRR), we can establish training zones that are specific to your unique physiology.

Heart Rate Training Zones

  • Fat Burning Zone (50-60%): Ideal for beginners or for long-duration recovery sessions. At this intensity, the body utilizes a higher percentage of fat for fuel.
  • Aerobic Zone (70-80%): This is the "sweet spot" for improving cardiovascular endurance and strengthening the heart muscle. It's effective for general fitness and weight loss.
  • Anaerobic Zone (85%+): Reserved for high-intensity interval training (HIIT) or performance athletes. This zone improves your VO2 max and lactic acid threshold.

Example Calculation

Suppose you are 40 years old with a resting heart rate of 70 BPM:

  1. Max HR: 220 – 40 = 180 BPM
  2. HR Reserve: 180 – 70 = 110 BPM
  3. 70% Intensity: (110 x 0.70) + 70 = 147 BPM

In this example, to train at a 70% aerobic intensity, the individual should aim for 147 beats per minute.

Tips for Success

For the most accurate results, measure your Resting Heart Rate first thing in the morning before you get out of bed. Use a pulse oximeter, a smartwatch, or manually count your pulse at your wrist (radial artery) for 60 seconds.

Note: Always consult with a healthcare professional before starting a new vigorous exercise program, especially if you have pre-existing heart conditions or are taking medications that affect heart rate (such as beta-blockers).

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