Fox Formula (Standard: 220 – Age)
Tanaka Formula (208 – 0.7 × Age)
Gulati Formula (Women: 206 – 0.88 × Age)
Haskell & Fox (Original)
Your Estimated Maximum Heart Rate:
0 BPM
Based on the selected formula.
Heart Rate Training Zones
Zone
Intensity
Range (BPM)
Understanding the Formula to Calculate Maximum Heart Rate
Knowing the formula to calculate maximum heart rate (MHR) is the cornerstone of effective cardiovascular training. Your maximum heart rate represents the highest number of beats per minute (BPM) your heart can achieve during maximal physical exertion. While a clinical stress test is the most accurate method, mathematical formulas provide a reliable estimate for the general population to establish safe training zones.
Common Formulas Used
Over the years, exercise physiologists have developed several equations. This calculator allows you to choose between the most scientifically validated methods:
Fox Formula (220 – Age): The most widely known and simple formula. It provides a good baseline for the general population but can overestimate MHR in younger people and underestimate it in older adults.
Tanaka Formula (208 – 0.7 × Age): Considered more accurate for healthy adults of varying ages. It smooths out the discrepancies found in the Fox formula.
Gulati Formula (206 – 0.88 × Age): Research specifically conducted on women suggested this formula is more accurate for female physiology than the traditional male-centric data.
Why Calculate Your Target Heart Rate Zones?
Once you have used the formula to calculate maximum heart rate, you can determine your training zones. Training in specific zones elicits different physiological adaptations:
Zone 1 (50-60%): Very light activity, warm-up, and recovery.
Zone 2 (60-70%): Fat burning and basic endurance building.
Zone 3 (70-80%): Aerobic fitness, improving blood circulation and skeletal muscle strength.
Zone 4 (80-90%): Anaerobic capacity, high-intensity performance training.
Zone 5 (90-100%): Maximum effort, suitable only for very short bursts (HIIT) for conditioned athletes.
Factors Affecting Maximum Heart Rate
While age is the primary variable in the formula to calculate maximum heart rate, other factors include genetics, altitude, and medication. Beta-blockers, for example, will lower your actual maximum heart rate regardless of what the formula predicts. Always consult a physician before starting a vigorous exercise program.
function calculateMaxHeartRate() {
// 1. Get Input Values
var ageInput = document.getElementById("mhrInputAge").value;
var formula = document.getElementById("mhrFormula").value;
// 2. Validate Input
if (ageInput === "" || isNaN(ageInput)) {
alert("Please enter a valid age.");
return;
}
var age = parseFloat(ageInput);
if (age 120) {
alert("Please enter a realistic age between 1 and 120.");
return;
}
// 3. Logic: Calculate MHR based on selected formula
var maxHeartRate = 0;
if (formula === "fox" || formula === "haskell") {
// Standard: 220 – Age
maxHeartRate = 220 – age;
} else if (formula === "tanaka") {
// Tanaka: 208 – (0.7 * Age)
maxHeartRate = 208 – (0.7 * age);
} else if (formula === "gulati") {
// Gulati: 206 – (0.88 * Age)
maxHeartRate = 206 – (0.88 * age);
}
// Round to nearest whole number
maxHeartRate = Math.round(maxHeartRate);
// 4. Logic: 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 DOM Results
document.getElementById("displayMHR").innerText = maxHeartRate;
var tableHTML = `