Cumulative Inflation Rate Calculator
This calculator helps you understand how the purchasing power of your money erodes over time due to inflation. By inputting the inflation rates for different periods, you can see the cumulative effect on the value of a sum of money.
Inflation Rate Year 1 (%):
Inflation Rate Year 2 (%):
Inflation Rate Year 3 (%):
Initial Amount:
Calculate
function calculateCumulativeInflation() {
var inflationRate1 = parseFloat(document.getElementById("inflationRate1").value);
var inflationRate2 = parseFloat(document.getElementById("inflationRate2").value);
var inflationRate3 = parseFloat(document.getElementById("inflationRate3").value);
var initialAmount = parseFloat(document.getElementById("initialAmount").value);
var resultElement = document.getElementById("result");
resultElement.innerHTML = ""; // Clear previous results
if (isNaN(inflationRate1) || isNaN(inflationRate2) || isNaN(inflationRate3) || isNaN(initialAmount) ||
inflationRate1 < 0 || inflationRate2 < 0 || inflationRate3 < 0 || initialAmount <= 0) {
resultElement.innerHTML = "Please enter valid positive numbers for all fields.";
return;
}
// Convert percentage rates to decimal factors
var factor1 = 1 + (inflationRate1 / 100);
var factor2 = 1 + (inflationRate2 / 100);
var factor3 = 1 + (inflationRate3 / 100);
// Calculate cumulative inflation factor
var cumulativeFactor = factor1 * factor2 * factor3;
// Calculate the value after inflation
var finalAmount = initialAmount / cumulativeFactor;
// Calculate the total percentage decrease in purchasing power
var totalInflationPercentage = ((initialAmount – finalAmount) / initialAmount) * 100;
resultElement.innerHTML =
"
Initial Amount: $" + initialAmount.toFixed(2) + "" +
"
Year 1 Inflation Rate: " + inflationRate1.toFixed(2) + "%" +
"
Year 2 Inflation Rate: " + inflationRate2.toFixed(2) + "%" +
"
Year 3 Inflation Rate: " + inflationRate3.toFixed(2) + "%" +
"
Cumulative Inflation Factor: " + cumulativeFactor.toFixed(4) + "" +
"
Value After 3 Years (Purchasing Power): $" + finalAmount.toFixed(2) + "" +
"
Total Decrease in Purchasing Power: " + totalInflationPercentage.toFixed(2) + "%";
}
.calculator-container {
font-family: sans-serif;
max-width: 600px;
margin: 20px auto;
padding: 20px;
border: 1px solid #ccc;
border-radius: 8px;
box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}
.calculator-container h2 {
text-align: center;
margin-bottom: 15px;
color: #333;
}
.input-section {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 15px;
align-items: center;
}
.input-section label {
font-weight: bold;
color: #555;
text-align: right;
padding-right: 10px;
}
.input-section input[type="number"] {
width: 100%;
padding: 8px;
border: 1px solid #ccc;
border-radius: 4px;
box-sizing: border-box; /* Important for width calculation */
}
.input-section button {
grid-column: 1 / -1; /* Span across both columns */
padding: 10px 15px;
background-color: #007bff;
color: white;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 16px;
margin-top: 10px;
transition: background-color 0.3s ease;
}
.input-section button:hover {
background-color: #0056b3;
}
#result {
margin-top: 25px;
padding: 15px;
border: 1px dashed #eee;
background-color: #f9f9f9;
border-radius: 4px;
}
#result p {
margin-bottom: 8px;
line-height: 1.5;
}
#result strong {
color: #333;
}