Bacterial Growth Rate Calculator
This calculator helps you determine the growth rate of a bacterial population over a specific period, assuming exponential growth. Understanding bacterial growth rate is crucial in fields like microbiology, medicine, and biotechnology for predicting contamination, optimizing fermentation processes, and studying the effects of antibiotics.
function calculateGrowthRate() {
var initialPopulation = parseFloat(document.getElementById("initialPopulation").value);
var finalPopulation = parseFloat(document.getElementById("finalPopulation").value);
var time = parseFloat(document.getElementById("time").value);
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = "; // Clear previous results
if (isNaN(initialPopulation) || isNaN(finalPopulation) || isNaN(time) || initialPopulation <= 0 || finalPopulation <= 0 || time <= 0) {
resultDiv.innerHTML = "Please enter valid positive numbers for all fields.";
return;
}
// The formula for exponential growth rate (k) is:
// N = N₀ * e^(k*t)
// where:
// N = final population
// N₀ = initial population
// e = Euler's number (approximately 2.71828)
// k = growth rate
// t = time
// Rearranging the formula to solve for k:
// N / N₀ = e^(k*t)
// ln(N / N₀) = k * t
// k = ln(N / N₀) / t
var growthRate = Math.log(finalPopulation / initialPopulation) / time;
resultDiv.innerHTML = "
Results:
" +
"Initial Population (N₀): " + initialPopulation.toLocaleString() + "" +
"Final Population (N): " + finalPopulation.toLocaleString() + "" +
"Time Elapsed (t): " + time + " hours" +
"
Bacterial Growth Rate (k): " + growthRate.toFixed(4) + " per hour";
}
.calculator-container {
font-family: sans-serif;
border: 1px solid #ccc;
padding: 20px;
border-radius: 8px;
max-width: 500px;
margin: 20px auto;
background-color: #f9f9f9;
}
.calculator-inputs {
display: grid;
grid-template-columns: 1fr;
gap: 15px;
margin-bottom: 20px;
}
.input-group {
display: flex;
flex-direction: column;
}
.input-group label {
margin-bottom: 5px;
font-weight: bold;
color: #333;
}
.input-group input[type="number"] {
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 1em;
}
.calculator-container button {
padding: 10px 15px;
background-color: #007bff;
color: white;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 1.1em;
transition: background-color 0.3s ease;
}
.calculator-container button:hover {
background-color: #0056b3;
}
.calculator-results {
margin-top: 20px;
padding: 15px;
border: 1px solid #eee;
border-radius: 4px;
background-color: #fff;
}
.calculator-results h3 {
margin-top: 0;
color: #333;
}
.calculator-results p {
margin-bottom: 8px;
color: #555;
}
.calculator-results strong {
color: #007bff;
}