Heart Rate Zone Calculator body { font-family: sans-serif; line-height: 1.6; } .calculator-container { border: 1px solid #ccc; padding: 20px; margin-bottom: 20px; } label { display: block; margin-bottom: 5px; font-weight: bold; } input[type="number"] { width: 100%; padding: 8px; margin-bottom: 15px; box-sizing: border-box; } button { padding: 10px 15px; background-color: #007bff; color: white; border: none; cursor: pointer; } button:hover { background-color: #0056b3; } #result { margin-top: 20px; padding: 15px; background-color: #e9ecef; border: 1px solid #ced4da; } h2 { color: #333; }

Heart Rate Zone Calculator

Age (Years): Resting Heart Rate (BPM):

Understanding Heart Rate Zones

Heart rate training is a popular and effective method for improving cardiovascular fitness, weight management, and athletic performance. By exercising within specific heart rate zones, you can target different physiological benefits.

What is Maximum Heart Rate (MHR)?

Your Maximum Heart Rate (MHR) is the highest number of times your heart can beat per minute during intense physical activity. A common and simple formula to estimate MHR is:

MHR = 220 – Age

This formula provides a good approximation, but individual MHR can vary. Factors like genetics, fitness level, and even medication can influence it.

What is Heart Rate Reserve (HRR)?

Heart Rate Reserve (HRR) is the difference between your MHR and your resting heart rate (RHR). It represents the range of heartbeats available for exercise.

HRR = MHR – Resting Heart Rate

Understanding the Heart Rate Zones:

These zones are typically expressed as a percentage of your MHR or as a percentage of your HRR added to your RHR. The latter method, using HRR, is often considered more personalized and accurate.

Zone 1: Very Light (50-60% of MHR)

Focus: Recovery, light aerobic activity.
Benefits: Aids in recovery from strenuous workouts, improves blood flow, and can help reduce stress.
Perceived Exertion: Very easy, can talk effortlessly.

Zone 2: Light (60-70% of MHR)

Focus: Building an aerobic base, endurance.
Benefits: Improves cardiovascular health, increases endurance, and burns fat effectively. This is often considered the "fat-burning zone."
Perceived Exertion: Comfortable, can talk in full sentences.

Zone 3: Moderate (70-80% of MHR)

Focus: Improving aerobic capacity and efficiency.
Benefits: Increases lung capacity, strengthens the heart, and improves overall fitness.
Perceived Exertion: Breathing becomes heavier, can speak in shorter sentences.

Zone 4: Hard (80-90% of MHR)

Focus: Improving anaerobic threshold and performance.
Benefits: Boosts speed and power, increases lactate threshold.
Perceived Exertion: Difficult to speak more than a few words.

Zone 5: Maximum (90-100% of MHR)

Focus: Peak performance, interval training.
Benefits: Significant improvements in speed and power, pushing your limits.
Perceived Exertion: Very hard, can barely speak.

function calculateHeartRateZones() { var age = parseFloat(document.getElementById("age").value); var restHeartRate = parseFloat(document.getElementById("rest_heart_rate").value); var resultDiv = document.getElementById("result"); resultDiv.innerHTML = ""; // Clear previous results if (isNaN(age) || isNaN(restHeartRate)) { resultDiv.innerHTML = "Please enter valid numbers for age and resting heart rate."; return; } if (age <= 0 || restHeartRate <= 0) { resultDiv.innerHTML = "Age and Resting Heart Rate must be positive numbers."; return; } var maxHeartRate = 220 – age; var heartRateReserve = maxHeartRate – restHeartRate; // Calculate zones based on MHR percentage var zone1_low_mhr = Math.round(maxHeartRate * 0.50); var zone1_high_mhr = Math.round(maxHeartRate * 0.60); var zone2_low_mhr = Math.round(maxHeartRate * 0.60); var zone2_high_mhr = Math.round(maxHeartRate * 0.70); var zone3_low_mhr = Math.round(maxHeartRate * 0.70); var zone3_high_mhr = Math.round(maxHeartRate * 0.80); var zone4_low_mhr = Math.round(maxHeartRate * 0.80); var zone4_high_mhr = Math.round(maxHeartRate * 0.90); var zone5_high_mhr = Math.round(maxHeartRate * 1.00); // Calculate zones based on HRR percentage + RHR var zone1_low_hrr = Math.round(restHeartRate + (heartRateReserve * 0.50)); var zone1_high_hrr = Math.round(restHeartRate + (heartRateReserve * 0.60)); var zone2_low_hrr = Math.round(restHeartRate + (heartRateReserve * 0.60)); var zone2_high_hrr = Math.round(restHeartRate + (heartRateReserve * 0.70)); var zone3_low_hrr = Math.round(restHeartRate + (heartRateReserve * 0.70)); var zone3_high_hrr = Math.round(restHeartRate + (heartRateReserve * 0.80)); var zone4_low_hrr = Math.round(restHeartRate + (heartRateReserve * 0.80)); var zone4_high_hrr = Math.round(restHeartRate + (heartRateReserve * 0.90)); var zone5_high_hrr = Math.round(restHeartRate + (heartRateReserve * 1.00)); var htmlOutput = "

Estimated Heart Rate Zones (BPM)

"; htmlOutput += "

Based on Maximum Heart Rate (MHR):

"; htmlOutput += "Estimated Maximum Heart Rate: " + maxHeartRate + " BPM"; htmlOutput += "

Zone 1 (Very Light): " + zone1_low_mhr + " – " + zone1_high_mhr + " BPM (50-60% of MHR)
Zone 2 (Light): " + zone2_low_mhr + " – " + zone2_high_mhr + " BPM (60-70% of MHR)
Zone 3 (Moderate): " + zone3_low_mhr + " – " + zone3_high_mhr + " BPM (70-80% of MHR)
Zone 4 (Hard): " + zone4_low_mhr + " – " + zone4_high_mhr + " BPM (80-90% of MHR)
Zone 5 (Maximum): " + zone4_high_mhr + " – " + zone5_high_mhr + " BPM (90-100% of MHR)