This calculator helps you determine the proportional amount of a monthly cost or income that applies to a specific period within that month. This is commonly used for prorating rent, subscriptions, or other recurring charges when a service or agreement begins or ends mid-month.
#proRataCalculator {
font-family: sans-serif;
max-width: 400px;
margin: 20px auto;
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 {
width: 100%;
padding: 8px;
box-sizing: border-box;
border: 1px solid #ccc;
border-radius: 4px;
}
button {
display: block;
width: 100%;
padding: 10px;
background-color: #4CAF50;
color: white;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 16px;
}
button:hover {
background-color: #45a049;
}
#result {
margin-top: 20px;
padding: 10px;
background-color: #f0f0f0;
border: 1px solid #ddd;
border-radius: 4px;
text-align: center;
font-weight: bold;
}
function calculateProRata() {
var totalMonthlyCost = parseFloat(document.getElementById("totalMonthlyCost").value);
var daysInMonth = parseInt(document.getElementById("daysInMonth").value);
var daysInPeriod = parseInt(document.getElementById("daysInPeriod").value);
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = ""; // Clear previous results
if (isNaN(totalMonthlyCost) || isNaN(daysInMonth) || isNaN(daysInPeriod)) {
resultDiv.innerHTML = "Please enter valid numbers for all fields.";
return;
}
if (daysInMonth <= 0 || daysInPeriod daysInMonth) {
resultDiv.innerHTML = "Days in pro rata period cannot be more than days in the month.";
return;
}
var dailyCost = totalMonthlyCost / daysInMonth;
var proRataAmount = dailyCost * daysInPeriod;
resultDiv.innerHTML = "Pro Rata Amount: " + proRataAmount.toFixed(2);
}