Measured while sitting quietly. Average is 60-80 BPM.
Your Personalized Zones
Estimated Max Heart Rate:–
Fat Burn Zone (60% – 70%):–
Aerobic Zone (70% – 80%):–
Anaerobic Zone (80% – 90%):–
Note: These calculations use the Karvonen Formula for higher accuracy based on your resting pulse.
How to Use the Fat Loss Heart Rate Calculator
Optimizing your workout for fat loss requires understanding heart rate zones. While any movement burns calories, the "Fat Burn Zone" is the intensity level where your body utilizes a higher percentage of energy from stored fat rather than glucose (carbohydrates).
Understanding the Calculation
This calculator uses the Karvonen Formula, which is more accurate than the standard "220 minus age" method because it accounts for your cardiovascular fitness level by including your Resting Heart Rate (RHR).
Max Heart Rate (MHR): The theoretical limit of your heart's capacity.
Heart Rate Reserve (HRR): The difference between your Max HR and Resting HR.
Fat Burn Zone: Calculated at 60% to 70% of your Heart Rate Reserve plus your Resting HR.
Example Calculation
If you are 30 years old with a resting heart rate of 60 BPM:
Max HR: 220 – 30 = 190 BPM
Heart Rate Reserve: 190 – 60 = 130 BPM
Fat Burn Low (60%): (130 x 0.60) + 60 = 138 BPM
Fat Burn High (70%): (130 x 0.70) + 60 = 151 BPM
In this example, your ideal fat-burning range is between 138 and 151 beats per minute.
Why the Fat Loss Zone Matters
Exercising within the 60-70% range is sustainable for longer durations. Longer workouts (45-60 minutes) at this intensity allow the body to mobilize fat stores efficiently. However, for maximum total calorie burn and metabolic health, many experts recommend mixing these steady-state sessions with higher-intensity intervals (Anaerobic Zone).
function calculateFatLossHR() {
var age = document.getElementById("ageInput").value;
var rhr = document.getElementById("restingHRInput").value;
var resultDiv = document.getElementById("hrResult");
if (age === "" || age <= 0) {
alert("Please enter a valid age.");
return;
}
if (rhr === "" || rhr <= 0) {
alert("Please enter your resting heart rate for a more accurate result.");
return;
}
// Standard Max Heart Rate
var maxHR = 220 – age;
// Karvonen Formula: Target HR = ((Max HR − Resting HR) × %Intensity) + Resting HR
var hrr = maxHR – rhr;
// Fat Burn Zone (60% – 70%)
var fatLow = Math.round((hrr * 0.60) + parseInt(rhr));
var fatHigh = Math.round((hrr * 0.70) + parseInt(rhr));
// Aerobic Zone (70% – 80%)
var aeroLow = Math.round((hrr * 0.70) + parseInt(rhr));
var aeroHigh = Math.round((hrr * 0.80) + parseInt(rhr));
// Anaerobic Zone (80% – 90%)
var anaLow = Math.round((hrr * 0.80) + parseInt(rhr));
var anaHigh = Math.round((hrr * 0.90) + parseInt(rhr));
// Update UI
document.getElementById("maxHRVal").innerHTML = maxHR + " BPM";
document.getElementById("fatBurnVal").innerHTML = fatLow + " – " + fatHigh + " BPM";
document.getElementById("aerobicVal").innerHTML = aeroLow + " – " + aeroHigh + " BPM";
document.getElementById("anaerobicVal").innerHTML = anaLow + " – " + anaHigh + " BPM";
// Show result
resultDiv.style.display = "block";
resultDiv.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}