Understanding your heart rate zones is crucial for effective and safe exercise. The Karvonen formula and simpler methods can help estimate your maximum heart rate (MHR). A common target zone for aerobic conditioning and fat burning is around 85% of your MHR. This calculator helps you quickly determine that specific heart rate value.
function calculate85PercentMHR() {
var ageInput = document.getElementById("age");
var resultDiv = document.getElementById("result");
var age = parseFloat(ageInput.value);
if (isNaN(age) || age 120) {
resultDiv.innerHTML = "Please enter a valid age.";
return;
}
// Simple Max Heart Rate Estimation Formula (220 – Age)
var maxHeartRate = 220 – age;
// Calculate 85% of Max Heart Rate
var eightyFivePercentMHR = maxHeartRate * 0.85;
resultDiv.innerHTML = "Estimated Maximum Heart Rate (MHR): " + maxHeartRate.toFixed(0) + " bpm" +
"85% of MHR (Target Heart Rate Zone): " + eightyFivePercentMHR.toFixed(0) + " bpm";
}