A pro-rated calculator helps determine the fair share of a cost or income when it's applied over a period that doesn't align perfectly with the billing cycle. This is common for services, rent, subscriptions, or insurance premiums that start or end mid-period. It ensures that you only pay for or receive what you're entitled to for the exact duration of service.
function calculateProRatedCost() {
var totalCost = parseFloat(document.getElementById("totalCost").value);
var periodDays = parseFloat(document.getElementById("periodDays").value);
var daysUsed = parseFloat(document.getElementById("daysUsed").value);
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = ""; // Clear previous results
if (isNaN(totalCost) || isNaN(periodDays) || isNaN(daysUsed) || periodDays <= 0 || daysUsed periodDays) {
resultDiv.innerHTML = "Error: Days used cannot be more than the total days in the period.";
return;
}
var costPerDay = totalCost / periodDays;
var proRatedCost = costPerDay * daysUsed;
resultDiv.innerHTML = "The pro-rated cost for " + daysUsed + " days is:
" + proRatedCost.toFixed(2) + "";
}
.calculator-inputs {
margin-bottom: 20px;
padding: 15px;
border: 1px solid #ccc;
border-radius: 5px;
}
.form-group {
margin-bottom: 15px;
}
.form-group label {
display: block;
margin-bottom: 5px;
font-weight: bold;
}
.form-group input[type="number"] {
width: calc(100% – 22px);
padding: 10px;
border: 1px solid #ccc;
border-radius: 3px;
}
button {
padding: 10px 15px;
background-color: #007bff;
color: white;
border: none;
border-radius: 5px;
cursor: pointer;
font-size: 16px;
}
button:hover {
background-color: #0056b3;
}
.calculator-result {
margin-top: 20px;
padding: 15px;
background-color: #e9ecef;
border: 1px solid #dee2e6;
border-radius: 5px;
}
.calculator-result p {
margin: 0;
}
.calculator-result strong {
color: #28a745;
}