.mhr-calculator-wrapper {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background: #fff;
color: #333;
}
.mhr-calc-container {
background-color: #f8f9fa;
border: 1px solid #e9ecef;
border-radius: 8px;
padding: 30px;
margin-bottom: 40px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.mhr-calc-title {
text-align: center;
color: #d63031;
margin-bottom: 25px;
font-size: 24px;
font-weight: 700;
}
.mhr-form-group {
margin-bottom: 20px;
}
.mhr-form-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #2d3436;
}
.mhr-form-control {
width: 100%;
padding: 12px;
border: 2px solid #dfe6e9;
border-radius: 6px;
font-size: 16px;
transition: border-color 0.3s;
box-sizing: border-box;
}
.mhr-form-control:focus {
border-color: #d63031;
outline: none;
}
.mhr-btn {
display: block;
width: 100%;
padding: 14px;
background-color: #d63031;
color: white;
border: none;
border-radius: 6px;
font-size: 18px;
font-weight: 700;
cursor: pointer;
transition: background-color 0.2s;
margin-top: 10px;
}
.mhr-btn:hover {
background-color: #b71c1c;
}
.mhr-results {
margin-top: 30px;
padding-top: 20px;
border-top: 2px dashed #dfe6e9;
display: none;
}
.mhr-main-result {
text-align: center;
font-size: 18px;
margin-bottom: 20px;
}
.mhr-bpm-display {
font-size: 42px;
font-weight: 800;
color: #d63031;
display: block;
margin: 10px 0;
}
.mhr-zones-table {
width: 100%;
border-collapse: collapse;
margin-top: 20px;
background: white;
border-radius: 6px;
overflow: hidden;
}
.mhr-zones-table th, .mhr-zones-table td {
padding: 12px 15px;
text-align: left;
border-bottom: 1px solid #eee;
}
.mhr-zones-table th {
background-color: #2d3436;
color: white;
font-weight: 600;
}
.mhr-zones-table tr:last-child td {
border-bottom: none;
}
.mhr-article {
line-height: 1.6;
color: #444;
}
.mhr-article h2 {
color: #2d3436;
margin-top: 30px;
font-size: 22px;
}
.mhr-article h3 {
color: #d63031;
font-size: 18px;
margin-top: 20px;
}
.mhr-article ul {
padding-left: 20px;
}
.mhr-article li {
margin-bottom: 10px;
}
.zone-color-1 { border-left: 5px solid #a8e6cf; }
.zone-color-2 { border-left: 5px solid #dcedc1; }
.zone-color-3 { border-left: 5px solid #ffd3b6; }
.zone-color-4 { border-left: 5px solid #ffaaa5; }
.zone-color-5 { border-left: 5px solid #ff8b94; }
How Do You Calculate Your Predicted Maximum Heart Rate?
Calculating your predicted Maximum Heart Rate (MHR) is a fundamental step in designing an effective and safe cardiovascular training program. Your MHR represents the upper limit of what your cardiovascular system can handle during physical exertion. While a clinical stress test is the most accurate method, several mathematical formulas provide reliable estimates based on age and gender.
Why Calculate MHR?
Knowing your maximum heart rate allows you to determine your specific Target Heart Rate Zones. Training in specific zones yields different physiological benefits:
- Fat Burning (Zone 2): Improves basic endurance and fat metabolism.
- Aerobic (Zone 3): Increases cardiovascular capacity and stamina.
- Anaerobic (Zone 4): Increases performance speed and lactic acid tolerance.
Common Calculation Methods
This calculator utilizes the most scientifically recognized formulas for predicting MHR:
1. The Fox Formula (Standard)
Formula: 220 – Age
This is the most traditional calculation used in fitness. While simple to calculate, it has a standard deviation of about 10-12 beats per minute, meaning it can sometimes underestimate MHR for fit older adults or overestimate it for younger individuals.
2. The Tanaka Formula
Formula: 208 – (0.7 × Age)
Published in 2001, the Tanaka equation is generally considered more accurate than the Fox formula, particularly for individuals over the age of 40. It smooths out the decline of heart rate max as we age.
3. The Gulati Formula (For Women)
Formula: 206 – (0.88 × Age)
Research has shown that the standard formulas often overestimate the maximum heart rate for women. The Gulati formula is specifically derived from data on women to provide a safer and more accurate training ceiling.
Safety Considerations
Please note that these calculations are estimates. Genetics, medications (like beta-blockers), and fitness levels can significantly alter your actual maximum heart rate. Always consult with a physician before beginning a vigorous exercise program, especially if you have a history of heart conditions.
function calculateHeartRate() {
// Get inputs
var ageInput = document.getElementById('mhr_age');
var methodSelect = document.getElementById('mhr_method');
var resultContainer = document.getElementById('mhr_result_container');
var displayVal = document.getElementById('mhr_display_val');
var zonesBody = document.getElementById('mhr_zones_body');
// Parse Age
var age = parseInt(ageInput.value);
// Validation
if (isNaN(age) || age 120) {
alert("Please enter a valid age between 1 and 120.");
return;
}
var method = methodSelect.value;
var maxHeartRate = 0;
// Calculate based on selected formula
if (method === 'fox') {
// Fox Formula: 220 – Age
maxHeartRate = 220 – age;
} else if (method === 'tanaka') {
// Tanaka Formula: 208 – (0.7 * Age)
maxHeartRate = 208 – (0.7 * age);
} else if (method === 'gulati') {
// Gulati Formula: 206 – (0.88 * Age)
maxHeartRate = 206 – (0.88 * age);
} else if (method === 'gellish') {
// Gellish Formula: 207 – (0.7 * Age)
maxHeartRate = 207 – (0.7 * age);
}
// Round to nearest whole number
maxHeartRate = Math.round(maxHeartRate);
// Display Main Result
displayVal.innerHTML = maxHeartRate + " BPM";
resultContainer.style.display = "block";
// Calculate Zones
// Zone 1: 50-60%
var z1_min = Math.round(maxHeartRate * 0.50);
var z1_max = Math.round(maxHeartRate * 0.60);
// Zone 2: 60-70%
var z2_min = Math.round(maxHeartRate * 0.60);
var z2_max = Math.round(maxHeartRate * 0.70);
// Zone 3: 70-80%
var z3_min = Math.round(maxHeartRate * 0.70);
var z3_max = Math.round(maxHeartRate * 0.80);
// Zone 4: 80-90%
var z4_min = Math.round(maxHeartRate * 0.80);
var z4_max = Math.round(maxHeartRate * 0.90);
// Zone 5: 90-100%
var z5_min = Math.round(maxHeartRate * 0.90);
var z5_max = maxHeartRate;
// Generate Table HTML
var html = ";
html += '