Your Target Heart Rate Zones
Enter your details above to see your target heart rate.
.calculator-container {
font-family: Arial, sans-serif;
max-width: 600px;
margin: 20px auto;
padding: 20px;
border: 1px solid #ccc;
border-radius: 8px;
box-shadow: 0 2px 5px rgba(0,0,0,0.1);
display: flex;
flex-wrap: wrap;
gap: 20px;
}
.calculator-inputs {
flex: 1;
min-width: 250px;
}
.calculator-results {
flex: 1;
min-width: 250px;
background-color: #f9f9f9;
padding: 15px;
border-radius: 5px;
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 5px;
font-weight: bold;
}
.input-group input[type="number"] {
width: calc(100% – 12px);
padding: 8px;
border: 1px solid #ccc;
border-radius: 4px;
box-sizing: border-box;
}
.input-group small {
font-size: 0.8em;
color: #666;
}
button {
background-color: #4CAF50;
color: white;
padding: 10px 15px;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 1em;
margin-top: 10px;
}
button:hover {
background-color: #45a049;
}
#result p {
margin: 0 0 10px 0;
line-height: 1.5;
}
#result strong {
font-weight: bold;
}
function calculateKarvonenHeartRate() {
var age = parseFloat(document.getElementById("age").value);
var restingHeartRate = parseFloat(document.getElementById("restingHeartRate").value);
var intensityLevel = parseFloat(document.getElementById("intensityLevel").value);
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = "; // Clear previous results
if (isNaN(age) || isNaN(restingHeartRate) || isNaN(intensityLevel)) {
resultDiv.innerHTML = "Please enter valid numbers for all fields.";
return;
}
if (age <= 0 || restingHeartRate <= 0 || intensityLevel 100) {
resultDiv.innerHTML = "Please enter valid values. Age and resting heart rate must be positive. Intensity must be between 1 and 100.";
return;
}
// Calculate Maximum Heart Rate (MHR) using a common formula
// Note: This is an estimation; MHR varies significantly between individuals.
// A common formula is 220 – age.
var maxHeartRate = 220 – age;
// Calculate Heart Rate Reserve (HRR)
var heartRateReserve = maxHeartRate – restingHeartRate;
// Calculate Target Heart Rate (THR) for the given intensity
var targetHeartRate = Math.round((intensityLevel / 100) * heartRateReserve + restingHeartRate);
// Display the results
var html = "
Estimated Maximum Heart Rate: " + maxHeartRate + " bpm
";
html += "This is an estimation and can vary.";
html += "
Target Heart Rate for " + intensityLevel + "% Intensity: " + targetHeartRate + " bpm";
// Display a typical training zone (e.g., 50-85% intensity)
var lowerZone = Math.round(0.50 * heartRateReserve + restingHeartRate);
var upperZone = Math.round(0.85 * heartRateReserve + restingHeartRate);
html += "
Recommended Training Zone (50%-85% Intensity):";
html += "
Low End (50%): " + lowerZone + " bpm";
html += "
High End (85%): " + upperZone + " bpm";
resultDiv.innerHTML = html;
}