300 Method Heart Rate Calculator
The 300 Method is a quick and easy way to estimate your heart rate when you have an electrocardiogram (ECG) or a rhythm strip with large boxes. This method is particularly useful for determining the rate of a regular rhythm. The principle is that there are approximately 300 large boxes in one minute of ECG paper if it were moving at the standard speed of 25 mm/sec.
Number of Large Boxes:
Calculate Heart Rate
function calculateHeartRate() {
var largeBoxesInput = document.getElementById("largeBoxes");
var resultDiv = document.getElementById("result");
var largeBoxes = parseFloat(largeBoxesInput.value);
if (isNaN(largeBoxes) || largeBoxes <= 0) {
resultDiv.innerHTML = "Please enter a valid number of large boxes (greater than 0).";
return;
}
var heartRate = 300 / largeBoxes;
resultDiv.innerHTML = "Estimated Heart Rate: " + heartRate.toFixed(0) + " bpm";
}
.calculator-container {
font-family: sans-serif;
border: 1px solid #ccc;
padding: 20px;
border-radius: 8px;
max-width: 400px;
margin: 20px auto;
box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
.calculator-container h2 {
text-align: center;
margin-bottom: 15px;
color: #333;
}
.calculator-container p {
margin-bottom: 20px;
line-height: 1.6;
color: #555;
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 8px;
font-weight: bold;
color: #444;
}
.input-group input[type="number"] {
width: calc(100% – 22px);
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 1rem;
}
button {
width: 100%;
padding: 12px;
background-color: #007bff;
color: white;
border: none;
border-radius: 4px;
font-size: 1.1rem;
cursor: pointer;
transition: background-color 0.3s ease;
}
button:hover {
background-color: #0056b3;
}
.result-container {
margin-top: 20px;
padding: 15px;
background-color: #e9ecef;
border: 1px solid #dee2e6;
border-radius: 4px;
text-align: center;
font-size: 1.2rem;
font-weight: bold;
color: #333;
}