Fixed Rate Method Calculator (Diminishing Balance Depreciation)
:root {
–primary-color: #2c3e50;
–accent-color: #3498db;
–light-bg: #f8f9fa;
–border-color: #e9ecef;
}
body {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
margin: 0;
padding: 20px;
}
.calculator-container {
max-width: 800px;
margin: 0 auto;
background: #fff;
padding: 30px;
border-radius: 8px;
box-shadow: 0 4px 6px rgba(0,0,0,0.1);
border: 1px solid var(–border-color);
}
.calc-header {
text-align: center;
margin-bottom: 25px;
}
.calc-header h2 {
margin: 0;
color: var(–primary-color);
}
.input-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
margin-bottom: 20px;
}
@media (max-width: 600px) {
.input-grid {
grid-template-columns: 1fr;
}
}
.form-group {
margin-bottom: 15px;
}
.form-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: var(–primary-color);
}
.form-group input {
width: 100%;
padding: 10px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.form-group input:focus {
border-color: var(–accent-color);
outline: none;
}
.calc-btn {
display: block;
width: 100%;
background: var(–accent-color);
color: white;
border: none;
padding: 12px;
font-size: 18px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
transition: background 0.2s;
margin-top: 10px;
}
.calc-btn:hover {
background: #2980b9;
}
#result-area {
margin-top: 30px;
display: none;
animation: fadeIn 0.5s;
}
.summary-box {
background: var(–light-bg);
padding: 20px;
border-radius: 6px;
border-left: 5px solid var(–accent-color);
margin-bottom: 25px;
display: grid;
grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
gap: 15px;
}
.summary-item {
text-align: center;
}
.summary-item strong {
display: block;
color: #7f8c8d;
font-size: 0.9em;
text-transform: uppercase;
margin-bottom: 5px;
}
.summary-item span {
display: block;
font-size: 1.4em;
font-weight: bold;
color: var(–primary-color);
}
.schedule-table {
width: 100%;
border-collapse: collapse;
margin-top: 15px;
font-size: 0.95em;
}
.schedule-table th, .schedule-table td {
padding: 10px;
border-bottom: 1px solid #ddd;
text-align: right;
}
.schedule-table th {
background-color: var(–primary-color);
color: white;
text-align: right;
}
.schedule-table th:first-child, .schedule-table td:first-child {
text-align: center;
}
.error-msg {
color: #e74c3c;
text-align: center;
margin-top: 10px;
display: none;
}
@keyframes fadeIn {
from { opacity: 0; transform: translateY(10px); }
to { opacity: 1; transform: translateY(0); }
}
.content-section {
max-width: 800px;
margin: 40px auto;
padding: 20px;
background: #fff;
}
.content-section h2 {
color: var(–primary-color);
border-bottom: 2px solid var(–border-color);
padding-bottom: 10px;
margin-top: 30px;
}
.content-section p, .content-section li {
color: #555;
}
Calculate Depreciation
Please enter valid positive numbers for all fields.
Total Written Down
$0.00
Final Book Value
$0.00
Depreciation Schedule
Year
Opening Value ($)
Depreciation Expense ($)
Closing Book Value ($)
function calculateFixedRate() {
// Get input elements
var costInput = document.getElementById("assetCost");
var rateInput = document.getElementById("depRate");
var yearsInput = document.getElementById("usefulLife");
var resultArea = document.getElementById("result-area");
var errorMsg = document.getElementById("errorMsg");
var scheduleBody = document.getElementById("scheduleBody");
var totalDepDisplay = document.getElementById("totalDepreciation");
var finalValueDisplay = document.getElementById("finalBookValue");
// Parse values
var cost = parseFloat(costInput.value);
var rate = parseFloat(rateInput.value);
var years = parseInt(yearsInput.value);
// Validation
if (isNaN(cost) || isNaN(rate) || isNaN(years) || cost < 0 || rate < 0 || years < 1) {
errorMsg.style.display = "block";
resultArea.style.display = "none";
return;
}
errorMsg.style.display = "none";
scheduleBody.innerHTML = "";
var currentBookValue = cost;
var totalDep = 0;
var rateDecimal = rate / 100;
// Generate schedule
for (var i = 1; i openingValue) {
depreciationAmount = openingValue;
}
var closingValue = openingValue – depreciationAmount;
// Accumulate totals
totalDep += depreciationAmount;
currentBookValue = closingValue;
// Create table row
var row = document.createElement("tr");
row.innerHTML =
"
" + i + " " +
"
" + openingValue.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2}) + " " +
"
" + depreciationAmount.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2}) + " " +
"
" + closingValue.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2}) + " ";
scheduleBody.appendChild(row);
if (currentBookValue <= 0) break;
}
// Update Summary
totalDepDisplay.innerHTML = "$" + totalDep.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
finalValueDisplay.innerHTML = "$" + currentBookValue.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
// Show results
resultArea.style.display = "block";
}
Understanding the Fixed Rate Method of Depreciation
The Fixed Rate Method , also known as the Diminishing Balance Method or Reducing Balance Method, is an accounting technique used to allocate the cost of an asset over its useful life. Unlike the Straight Line method, which spreads the cost evenly, the Fixed Rate Method charges a higher amount of depreciation in the early years of an asset's life and less in later years.
How the Formula Works
The core logic behind the Fixed Rate Method is applying a constant percentage rate to the Written Down Value (WDV) or Book Value of the asset at the beginning of each year. The formula for the depreciation expense in any given year is:
Depreciation Expense = Book Value (at start of year) × Rate (%)
Because the book value decreases every year, the depreciation expense also decreases over time. This method is particularly useful for:
Technology & Electronics: Assets that lose value quickly due to obsolescence (e.g., computers, smartphones).Vehicles & Machinery: Assets that require more maintenance as they age; lower depreciation in later years offsets higher repair costs.
Example Calculation
Suppose you purchase a piece of machinery for $20,000 and depreciate it at a fixed rate of 20% per year.
Year 1: $20,000 × 20% = $4,000 Depreciation. (Closing Value: $16,000)Year 2: $16,000 × 20% = $3,200 Depreciation. (Closing Value: $12,800)Year 3: $12,800 × 20% = $2,560 Depreciation. (Closing Value: $10,240)
As shown, the expense reduces each year, reflecting the diminishing utility or value of the asset.
Fixed Rate Method vs. Straight Line Method
The main difference lies in the consistency of the expense:
Straight Line (Fixed Installment): Depreciation amount is constant every year. Ideal for furniture or buildings.Fixed Rate (Diminishing Balance): Depreciation percentage is constant, but the dollar amount decreases. Ideal for high-efficiency assets.