Calculate how inflation changes the value of money over time
Relative Purchasing Power:
$0.00
Cumulative Inflation: 0%
Understanding the Real Value of a Dollar
This calculator determines the purchasing power of the U.S. Dollar by analyzing the Consumer Price Index (CPI). Inflation is the rate at which the general level of prices for goods and services rises, and subsequently, purchasing power falls.
How It Works
The calculation uses the official Bureau of Labor Statistics (BLS) CPI data. The formula used is:
Value in Target Year = (Amount × Target Year CPI) / Starting Year CPI
Practical Example
If you have $100 in 1980, it would be equivalent to approximately $382 in 2024. This means what cost $100 in 1980 would require nearly four times as much cash today to acquire the same basket of goods. Conversely, $100 today would only have had about $26 worth of purchasing power in 1980 terms.
Why This Matters
Retirement Planning: Understanding that $1 million today will buy much less in 30 years.
Wage Negotiations: Ensuring salary increases keep pace with the "real" value of money.
Investment Returns: Calculating "real returns" by subtracting inflation from nominal gains.
// CPI Data (Annual Averages)
var cpiData = {
1950: 24.1, 1951: 26.0, 1952: 26.5, 1953: 26.7, 1954: 26.9, 1955: 26.8, 1956: 27.2, 1957: 28.1, 1958: 28.9, 1959: 29.1,
1960: 29.6, 1961: 29.9, 1962: 30.2, 1963: 30.6, 1964: 31.0, 1965: 31.5, 1966: 32.4, 1967: 33.4, 1968: 34.8, 1969: 36.7,
1970: 38.8, 1971: 40.5, 1972: 41.8, 1973: 44.4, 1974: 49.3, 1975: 53.8, 1976: 56.9, 1977: 60.6, 1978: 65.2, 1979: 72.6,
1980: 82.4, 1981: 90.9, 1982: 96.5, 1983: 99.6, 1984: 103.9, 1985: 107.6, 1986: 109.6, 1987: 113.6, 1988: 118.3, 1989: 124.0,
1990: 130.7, 1991: 136.2, 1992: 140.3, 1993: 144.5, 1994: 148.2, 1995: 152.4, 1996: 156.9, 1997: 160.5, 1998: 163.0, 1999: 166.6,
2000: 172.2, 2001: 177.1, 2002: 179.9, 2003: 184.0, 2004: 188.9, 2005: 195.3, 2006: 201.6, 2007: 207.3, 2008: 215.3, 2009: 214.5,
2010: 218.1, 2011: 224.9, 2012: 229.6, 2013: 233.0, 2014: 236.7, 2015: 237.0, 2016: 240.0, 2017: 245.1, 2018: 251.1, 2019: 255.7,
2020: 258.8, 2021: 271.0, 2022: 292.7, 2023: 304.7, 2024: 314.1
};
function init() {
var startSelect = document.getElementById('startYear');
var endSelect = document.getElementById('endYear');
var years = Object.keys(cpiData).sort();
for (var i = 0; i < years.length; i++) {
var optStart = document.createElement('option');
optStart.value = years[i];
optStart.innerHTML = years[i];
startSelect.appendChild(optStart);
var optEnd = document.createElement('option');
optEnd.value = years[i];
optEnd.innerHTML = years[i];
endSelect.appendChild(optEnd);
}
// Set defaults
startSelect.value = "1980";
endSelect.value = "2024";
}
function calculateValue() {
var amount = parseFloat(document.getElementById('initialAmount').value);
var startYear = document.getElementById('startYear').value;
var endYear = document.getElementById('endYear').value;
if (isNaN(amount) || amount 0) {
statText = "Cumulative Inflation: " + inflationRate.toFixed(2) + "%";
document.getElementById('inflationStat').style.color = "#dc2626";
document.getElementById('resultTitle').innerHTML = "$" + amount.toLocaleString() + " in " + startYear + " is equivalent to this in " + endYear + ":";
} else if (inflationRate < 0) {
statText = "Cumulative Deflation: " + Math.abs(inflationRate).toFixed(2) + "%";
document.getElementById('inflationStat').style.color = "#059669";
document.getElementById('resultTitle').innerHTML = "$" + amount.toLocaleString() + " in " + startYear + " is equivalent to this in " + endYear + ":";
} else {
statText = "No change in price levels.";
document.getElementById('inflationStat').style.color = "#374151";
document.getElementById('resultTitle').innerHTML = "No change between years.";
}
document.getElementById('inflationStat').innerHTML = statText;
}
// Run init on load
init();