body {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
max-width: 800px;
margin: 0 auto;
padding: 20px;
}
.calc-container {
background-color: #f8f9fa;
border: 1px solid #e9ecef;
border-radius: 8px;
padding: 30px;
margin-bottom: 40px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.calc-header {
text-align: center;
margin-bottom: 25px;
}
.calc-header h2 {
margin: 0;
color: #2c3e50;
}
.form-group {
margin-bottom: 20px;
}
.form-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #495057;
}
.input-wrapper {
position: relative;
}
.input-wrapper input {
width: 100%;
padding: 12px;
border: 1px solid #ced4da;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.currency-symbol {
position: absolute;
left: 12px;
top: 50%;
transform: translateY(-50%);
color: #6c757d;
}
.input-with-icon {
padding-left: 30px !important;
}
.btn-calc {
display: block;
width: 100%;
padding: 14px;
background-color: #007bff;
color: white;
border: none;
border-radius: 4px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background-color 0.2s;
}
.btn-calc:hover {
background-color: #0056b3;
}
.result-box {
margin-top: 30px;
padding: 20px;
background-color: #ffffff;
border: 1px solid #dee2e6;
border-radius: 6px;
display: none;
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
padding-bottom: 10px;
border-bottom: 1px solid #f1f3f5;
}
.result-row:last-child {
border-bottom: none;
margin-bottom: 0;
padding-bottom: 0;
}
.result-label {
color: #6c757d;
}
.result-value {
font-weight: bold;
color: #212529;
}
.result-highlight {
font-size: 24px;
color: #28a745;
}
.error-msg {
color: #dc3545;
display: none;
margin-top: 10px;
font-size: 14px;
}
.article-content {
background: #fff;
padding: 20px 0;
}
.article-content h2 {
color: #2c3e50;
border-bottom: 2px solid #007bff;
padding-bottom: 10px;
margin-top: 30px;
}
.article-content h3 {
color: #495057;
margin-top: 25px;
}
.article-content ul {
padding-left: 20px;
}
.article-content li {
margin-bottom: 10px;
}
.example-box {
background-color: #e9ecef;
padding: 15px;
border-left: 4px solid #17a2b8;
margin: 20px 0;
}
function calculateRefund() {
var totalCostInput = document.getElementById('totalCost').value;
var totalDurationInput = document.getElementById('totalDuration').value;
var timeUsedInput = document.getElementById('timeUsed').value;
var errorMsg = document.getElementById('errorMsg');
var resultBox = document.getElementById('resultBox');
// Reset display
errorMsg.style.display = 'none';
resultBox.style.display = 'none';
// Validation
if (totalCostInput === " || totalDurationInput === " || timeUsedInput === ") {
errorMsg.innerText = "Please fill in all fields.";
errorMsg.style.display = 'block';
return;
}
var totalCost = parseFloat(totalCostInput);
var totalDuration = parseFloat(totalDurationInput);
var timeUsed = parseFloat(timeUsedInput);
if (isNaN(totalCost) || isNaN(totalDuration) || isNaN(timeUsed)) {
errorMsg.innerText = "Please enter valid numeric values.";
errorMsg.style.display = 'block';
return;
}
if (totalDuration <= 0) {
errorMsg.innerText = "Total duration must be greater than zero.";
errorMsg.style.display = 'block';
return;
}
if (timeUsed totalDuration) {
errorMsg.innerText = "Time used cannot exceed the total contract length.";
errorMsg.style.display = 'block';
return;
}
// Calculation Logic
// Rate per unit of time (e.g., cost per day or per month)
var ratePerUnit = totalCost / totalDuration;
// Cost incurred for the time used
var costIncurred = ratePerUnit * timeUsed;
// Refund amount (Total – Incurred)
var refundAmount = totalCost – costIncurred;
// Display Results
document.getElementById('displayRate').innerText = '$' + ratePerUnit.toFixed(2);
document.getElementById('displayUsed').innerText = '$' + costIncurred.toFixed(2);
document.getElementById('displayRefund').innerText = '$' + refundAmount.toFixed(2);
resultBox.style.display = 'block';
}
Understanding Pro-rated Refunds
A Pro-rated Refund is a partial reimbursement provided to a customer when a service or contract is terminated early. The amount is calculated based on the "unused" portion of the service term. This ensures that the customer only pays for the time they actually used the service, while the provider is compensated for the period the service was active.
This type of calculation is standard in many industries, including:
- Insurance Policies: Cancelling car or home insurance mid-term.
- SaaS Subscriptions: Downgrading or cancelling annual software licenses.
- Rent & Leasing: Moving out before the end of the month.
- Tuition: Withdrawing from classes early in the semester.
The Pro-ration Formula
The logic behind calculating a pro-rated refund is straightforward. It establishes a daily or monthly unit price based on the total contract value and multiplies the remaining time by that unit price.
Formula:
(Total Cost ÷ Total Duration) × Remaining Time = Refund Amount
Real-World Example: Gym Membership
Imagine you paid $600 upfront for a 1-year (12 month) gym membership. However, you are moving to a new city after just 3 months.
To calculate your refund:
- Determine Unit Cost: $600 ÷ 12 months = $50 per month.
- Calculate Usage Cost: $50 × 3 months used = $150.
- Calculate Refund: $600 (Total) – $150 (Used) = $450 Refund.
Why "Days" vs "Months" Matters
When using the calculator above, consistency is key. If your contract is defined in days (e.g., 365 days), you should input your "Time Used" in days. If your contract is monthly, input both values in months.
Using days is generally more accurate. For example, cancelling on the 15th of February (a 28-day month) might yield a different daily rate than cancelling on the 15th of March (a 31-day month) if the vendor calculates based on the exact number of days in the year.
Common Refund Policies
While the math is objective, company policies are subjective. Always check the terms of service. Some companies charge a cancellation fee which is deducted from the pro-rated amount. Others may not offer pro-rated refunds at all, adhering to a "no refunds" policy for pre-paid periods.