How to Calculate Target Heart Rate Formula

Target Heart Rate Calculator

70%

Moderate: 50-70% | Vigorous: 70-85%

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How to Calculate Target Heart Rate Formula

Understanding your target heart rate (THR) is essential for maximizing cardiovascular benefits and ensuring safety during exercise. The most accurate way to calculate this manually is through the Karvonen Formula, which takes your resting heart rate into account to find your Heart Rate Reserve.

The Karvonen Formula Breakdown

The calculation follows three specific steps:

1. Find your Maximum Heart Rate (MHR): 220 – Age = MHR
2. Find your Heart Rate Reserve (HRR): MHR – Resting Heart Rate = HRR
3. Calculate Target Heart Rate (THR): (HRR × Intensity%) + Resting Heart Rate = THR

Real-World Example

If you are a 40-year-old individual with a resting heart rate of 60 BPM and you want to exercise at 70% intensity, the math looks like this:

• 1. Max HR: 220 – 40 = 180 BPM
• 2. HR Reserve: 180 – 60 = 120 BPM
• 3. Target HR: (120 × 0.70) + 60 = 144 BPM

In this example, to maintain a 70% intensity level, the individual should aim for a pulse of approximately 144 beats per minute.

Target Zones for Fitness Goals

Depending on your health goals, you may want to adjust your intensity level:

• Weight Management (50-60%): Lower intensity, ideal for beginners or long-duration activity.
• Aerobic Fitness (70-80%): Enhances cardiovascular endurance and lung capacity.
• Peak Performance (85-95%): High-intensity interval training (HIIT) to increase speed and power.

function calculateTHR() { var age = parseFloat(document.getElementById("age").value); var rhr = parseFloat(document.getElementById("restingHR").value); var intensity = parseFloat(document.getElementById("intensity").value) / 100; if (isNaN(age) || isNaN(rhr) || age <= 0 || rhr <= 0) { alert("Please enter valid positive numbers for Age and Resting Heart Rate."); return; } // MHR = 220 – Age var mhr = 220 – age; // HRR = MHR – RHR var hrr = mhr – rhr; // THR = (HRR * Intensity) + RHR var thr = (hrr * intensity) + rhr; // Update UI document.getElementById("maxHRResult").innerText = Math.round(mhr); document.getElementById("targetHRResult").innerText = Math.round(thr); var zoneText = ""; var intensityPct = intensity * 100; if (intensityPct < 60) { zoneText = "You are in the Light/Warm-up zone."; } else if (intensityPct < 70) { zoneText = "You are in the Weight Control/Fat Burn zone."; } else if (intensityPct < 85) { zoneText = "You are in the Aerobic/Endurance zone."; } else { zoneText = "You are in the Anaerobic/Peak Performance zone."; } document.getElementById("hrZoneInfo").innerText = zoneText; document.getElementById("results").style.display = "block"; }