Estimate your maximum heart rate and determine your optimal training zones.
Fox Formula (220 – Age) – Standard
Tanaka Formula (208 – 0.7 × Age) – Accurate for 40+
Gulati Formula (206 – 0.88 × Age) – Women Specific
Hunt Formula (211 – 0.64 × Age) – Active Adults
Estimated Max Heart Rate:
0 BPM
Your Training Zones
Zone
Intensity (%)
Heart Rate Range (BPM)
Benefit
function calculateMHR() {
// 1. Get input values
var ageInput = document.getElementById('mhr-age').value;
var formula = document.getElementById('mhr-formula').value;
var resultArea = document.getElementById('mhr-result-area');
var displayValue = document.getElementById('mhr-display-value');
var tableBody = document.getElementById('mhr-table-body');
// 2. Validate Input
var age = parseFloat(ageInput);
if (!age || isNaN(age) || age 120) {
alert("Please enter a valid age between 1 and 120.");
return;
}
// 3. Calculate Max Heart Rate based on formula
var maxHeartRate = 0;
if (formula === 'fox') {
// Fox Formula: 220 – Age
maxHeartRate = 220 – age;
} else if (formula === 'tanaka') {
// Tanaka Formula: 208 – (0.7 x Age)
maxHeartRate = 208 – (0.7 * age);
} else if (formula === 'gulati') {
// Gulati Formula: 206 – (0.88 x Age)
maxHeartRate = 206 – (0.88 * age);
} else if (formula === 'hunt') {
// Hunt Formula: 211 – (0.64 x Age)
maxHeartRate = 211 – (0.64 * age);
}
// Round the result
maxHeartRate = Math.round(maxHeartRate);
// 4. 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;
// 5. Update HTML Output
displayValue.innerHTML = maxHeartRate + " BPM";
resultArea.style.display = "block";
// Generate Table Rows
var html = ";
// Zone 1
html += '
';
html += '
Zone 1 (Very Light)
';
html += '
50% – 60%
';
html += '
' + z1_min + ' – ' + z1_max + '
';
html += '
Warm up, recovery, improves overall health.
';
html += '
';
// Zone 2
html += '
';
html += '
Zone 2 (Light)
';
html += '
60% – 70%
';
html += '
' + z2_min + ' – ' + z2_max + '
';
html += '
Fat burning, improves basic endurance.
';
html += '
';
// Zone 3
html += '
';
html += '
Zone 3 (Moderate)
';
html += '
70% – 80%
';
html += '
' + z3_min + ' – ' + z3_max + '
';
html += '
Improves aerobic fitness and stamina.
';
html += '
';
// Zone 4
html += '
';
html += '
Zone 4 (Hard)
';
html += '
80% – 90%
';
html += '
' + z4_min + ' – ' + z4_max + '
';
html += '
Increases maximum performance capacity.
';
html += '
';
// Zone 5
html += '
';
html += '
Zone 5 (Maximum)
';
html += '
90% – 100%
';
html += '
' + z5_min + ' – ' + z5_max + '
';
html += '
Speed / sprinting, develops fast twitch fibers.
';
html += '
';
tableBody.innerHTML = html;
}
How Is Max Heart Rate Calculated?
Calculating your Maximum Heart Rate (MHR) is a fundamental step in designing an effective cardiovascular training program. Your MHR represents the highest number of beats per minute (BPM) your heart can achieve during maximum physical exertion. While the only 100% accurate way to determine this is a clinical stress test, several mathematical formulas provide reliable estimates for the general population.
Common Formulas for Calculating Max Heart Rate
Over the years, exercise physiologists have developed various equations to estimate MHR based on age. The calculator above utilizes the four most prominent methods:
Fox Formula (220 – Age): This is the most traditional and widely used calculation. While easy to remember, it tends to overestimate MHR in younger people and underestimate it in older adults.
Tanaka Formula (208 – 0.7 × Age): Developed in 2001, this regression equation is considered more accurate for healthy adults over the age of 40 compared to the Fox formula.
Gulati Formula (206 – 0.88 × Age): Research has shown that the standard formulas often overestimate MHR for women. The Gulati formula is specifically calibrated for female physiology.
Hunt Formula (211 – 0.64 × Age): A newer formula derived from active adults, often preferred by those who engage in regular fitness training.
Understanding Heart Rate Zones
Once you have calculated your MHR, you can determine your training zones. Training in specific heart rate zones yields different physiological benefits:
Zone 1: Very Light (50-60%)
Used for warm-ups, cool-downs, and active recovery. Training here aids in recovery and prepares the body for more intense activity without placing significant stress on the cardiovascular system.
Zone 2: Light (60-70%)
Often referred to as the "Fat Burning Zone." In this zone, the body relies primarily on fat stores for energy. It builds a solid endurance base and improves the body's ability to transport oxygen.
Zone 3: Moderate (70-80%)
The "Aerobic Zone." Training here improves cardiovascular endurance and muscle strength. It is the sweet spot for improving general fitness and stamina.
Zone 4: Hard (80-90%)
The "Anaerobic Threshold." At this intensity, your body begins to produce lactic acid faster than it can clear it. Training here improves your ability to sustain high-speed efforts and increases your VO2 max.
Zone 5: Maximum (90-100%)
Reserved for short bursts of maximum effort, such as sprinting. This zone places high stress on the body and is used to develop speed and neuromuscular power. It should be used sparingly and by experienced athletes.
Factors Affecting Max Heart Rate
It is important to remember that these calculations are estimates. Several factors can influence your actual MHR, including:
Genetics: The primary determinant of your MHR.
Altitude: High altitudes can temporarily lower your MHR capacity.
Medications: Beta-blockers and other medications can significantly lower heart rate.
Fitness Level: While training lowers your resting heart rate, it does not significantly change your maximum heart rate, though elite athletes may have a slightly lower MHR than sedentary individuals of the same age.