The Consumer Price Index (CPI) tracks average price changes, but your personal spending habits define your actual cost-of-living increase. Use this tool to compare your monthly expenses from 12 months ago to today.
Expense Category
Cost Last Year ($)
Cost This Year ($)
Your Results
Understanding Your Personal Inflation Rate
While government agencies like the Bureau of Labor Statistics publish the Consumer Price Index (CPI), this number is a broad average. It tracks a "basket of goods" that might not represent your life. If you don't drive, the spike in gasoline prices doesn't affect your personal inflation. If you own your home outright, rising rent prices are irrelevant to your budget.
The Formula Behind the Calculation
Calculating your personal inflation rate follows a simple percentage change formula based on your total expenditures:
((Total Expenses Current Year – Total Expenses Last Year) / Total Expenses Last Year) x 100
Example Scenario
Imagine your monthly expenses last year looked like this:
Housing: $1,500
Groceries: $400
Total: $1,900
This year, your rent stayed the same, but groceries jumped to $500:
Housing: $1,500
Groceries: $500
Total: $2,000
Your personal inflation rate would be: (($2,000 – $1,900) / $1,900) * 100 = 5.26%. Even if the national CPI is 8%, your personal experience is lower because your major expense (housing) remained stable.
Why This Matters for Financial Planning
Budgeting: If your rate is higher than your annual raise, you are effectively taking a pay cut.
Retirement Planning: Estimating future costs based on your specific lifestyle rather than generic averages leads to more accurate savings goals.
Spending Habits: Identifying which categories are rising fastest allows you to seek alternatives (e.g., switching from beef to chicken or using public transit).
function calculateInflation() {
var hL = parseFloat(document.getElementById('housingLast').value) || 0;
var hN = parseFloat(document.getElementById('housingNow').value) || 0;
var fL = parseFloat(document.getElementById('foodLast').value) || 0;
var fN = parseFloat(document.getElementById('foodNow').value) || 0;
var tL = parseFloat(document.getElementById('transportLast').value) || 0;
var tN = parseFloat(document.getElementById('transportNow').value) || 0;
var uL = parseFloat(document.getElementById('utilLast').value) || 0;
var uN = parseFloat(document.getElementById('utilNow').value) || 0;
var mL = parseFloat(document.getElementById('healthLast').value) || 0;
var mN = parseFloat(document.getElementById('healthNow').value) || 0;
var oL = parseFloat(document.getElementById('otherLast').value) || 0;
var oN = parseFloat(document.getElementById('otherNow').value) || 0;
var totalLast = hL + fL + tL + uL + mL + oL;
var totalNow = hN + fN + tN + uN + mN + oN;
var resultDiv = document.getElementById('inflationResult');
var totalChangeText = document.getElementById('totalChangeText');
var breakdownText = document.getElementById('breakdownText');
if (totalLast === 0) {
alert("Please enter your expenses from last year to calculate the rate of change.");
return;
}
var percentageChange = ((totalNow – totalLast) / totalLast) * 100;
var difference = totalNow – totalLast;
resultDiv.style.display = 'block';
var color = percentageChange > 0 ? "#d93025" : "#188038";
var status = percentageChange > 0 ? "Increase" : "Decrease";
totalChangeText.innerHTML = "Your Personal Inflation Rate: " + percentageChange.toFixed(2) + "%";
breakdownText.innerHTML = "Your total monthly spending went from $" + totalLast.toLocaleString() + " to $" + totalNow.toLocaleString() + "." +
"This represents a monthly " + status + " of $" + Math.abs(difference).toLocaleString() + " in your cost of living." +
"Note: This calculation assumes the volume of goods/services purchased remained the same. If you bought more items this year, your 'inflation' includes lifestyle creep.";
resultDiv.scrollIntoView({ behavior: 'smooth' });
}