Determine your maximum heart rate (MHR) and training zones.
Male
Female
Tanaka (Recommended for accuracy)
Fox (Standard: 220 – Age)
Gulati (Specific for Women)
Maximum Predicted Heart Rate
0 BPM
Your Training Zones
Zone
Intensity
Range (BPM)
Benefit
Understanding Your Maximum Heart Rate
Your Maximum Heart Rate (MHR) is the highest number of beats per minute your heart can achieve during maximum physical exertion. Knowing this number is the cornerstone of heart-rate-based training, allowing you to define specific intensity zones to improve endurance, burn fat, or increase speed.
Why Calculate MHR?
Exercising without knowing your heart rate zones is like driving a car without a speedometer. You might feel like you are going fast, but you may not be in the optimal zone for your goals.
Safety: Ensures you don't overexert yourself, especially if you are new to fitness.
Efficiency: Helps you train in the "fat burning" zone or "cardio" zone depending on your objectives.
Progress Tracking: As you get fitter, your resting heart rate drops, but your MHR generally remains determined by age and genetics.
Note: Predicted MHR formulas are estimations. The only way to determine your true max heart rate with 100% accuracy is through a graded exercise stress test conducted by a medical professional.
The Formulas Used
This calculator offers three primary scientific formulas to predict your MHR:
1. The Tanaka Formula (Recommended)
Formula: 208 – (0.7 × Age)
Published in 2001, this formula is generally considered more accurate for a wider range of ages and fitness levels than the traditional Fox formula.
2. The Fox Formula (Standard)
Formula: 220 – Age
This is the oldest and most commonly cited formula. While simple to calculate mentally, it tends to underestimate MHR for older adults and overestimate it for younger individuals.
3. The Gulati Formula (For Women)
Formula: 206 – (0.88 × Age)
Research published in 2010 suggested that the traditional calculation overestimates maximum heart rate in women. The Gulati formula is specifically derived to predict MHR more accurately for females.
Heart Rate Training Zones
Once you have your MHR, you can utilize training zones:
Zone 1 (50-60%): Very Light. Good for warm-ups and recovery.
Zone 2 (60-70%): Light. The "Fat Burning" zone. Builds basic endurance.
Zone 3 (70-80%): Moderate. Improves aerobic capacity and blood circulation.
Zone 4 (80-90%): Hard. Increases maximum performance capacity.
Zone 5 (90-100%): Maximum. Develops maximum speed and power (short bursts).
function calculateHeartRate() {
// 1. Get Input Values
var ageInput = document.getElementById('inputAge').value;
var gender = document.getElementById('inputGender').value;
var formula = document.getElementById('inputFormula').value;
// 2. Validation
if (!ageInput || ageInput <= 0) {
alert("Please enter a valid age.");
return;
}
var age = parseFloat(ageInput);
var mhr = 0;
// 3. Logic based on formula selection
if (formula === 'fox') {
mhr = 220 – age;
} else if (formula === 'tanaka') {
mhr = 208 – (0.7 * age);
} else if (formula === 'gulati') {
// Gulati is specifically for women, but we calculate it regardless if selected
mhr = 206 – (0.88 * age);
}
// Round to nearest whole number
mhr = Math.round(mhr);
// 4. Calculate Zones
var zone1Low = Math.round(mhr * 0.50);
var zone1High = Math.round(mhr * 0.60);
var zone2Low = Math.round(mhr * 0.60);
var zone2High = Math.round(mhr * 0.70);
var zone3Low = Math.round(mhr * 0.70);
var zone3High = Math.round(mhr * 0.80);
var zone4Low = Math.round(mhr * 0.80);
var zone4High = Math.round(mhr * 0.90);
var zone5Low = Math.round(mhr * 0.90);
var zone5High = mhr;
// 5. Update UI
document.getElementById('mhrResult').innerText = mhr;
document.getElementById('results-area').style.display = 'block';
// Build Table HTML
var tableHtml = '';
// Zone 5
tableHtml += '
';
tableHtml += '
Zone 5
';
tableHtml += '
Maximum
';
tableHtml += '
' + zone5Low + ' – ' + zone5High + '
';
tableHtml += '
Speed & Power
';
tableHtml += '
';
// Zone 4
tableHtml += '
';
tableHtml += '
Zone 4
';
tableHtml += '
Hard
';
tableHtml += '
' + zone4Low + ' – ' + zone4High + '
';
tableHtml += '
Anaerobic Capacity
';
tableHtml += '
';
// Zone 3
tableHtml += '
';
tableHtml += '
Zone 3
';
tableHtml += '
Moderate
';
tableHtml += '
' + zone3Low + ' – ' + zone3High + '
';
tableHtml += '
Aerobic Fitness
';
tableHtml += '
';
// Zone 2
tableHtml += '
';
tableHtml += '
Zone 2
';
tableHtml += '
Light
';
tableHtml += '
' + zone2Low + ' – ' + zone2High + '
';
tableHtml += '
Fat Burning & Endurance
';
tableHtml += '
';
// Zone 1
tableHtml += '
';
tableHtml += '
Zone 1
';
tableHtml += '
Very Light
';
tableHtml += '
' + zone1Low + ' – ' + zone1High + '
';
tableHtml += '
Warm up & Recovery
';
tableHtml += '
';
document.getElementById('zonesBody').innerHTML = tableHtml;
// Optional: Warn if male selects Gulati
if (gender === 'male' && formula === 'gulati') {
alert("Note: The Gulati formula is scientifically designed for women. The result may not be accurate for men.");
}
}