Inflation Calculator

Nearly every free inflation calculator hands you one number and stops. Type in $100 from 2000, get back about $187 in today's money, done. As a museum fact that's fine, but a lone number quietly lies to you two ways, and this one was built to catch both.

First, one figure tells you nothing about whether it's alarming or ordinary. Prices up 87 percent over a quarter century sounds brutal, until you notice it's about 2.5 percent a year, which is dull, even though both numbers describe the exact same reality. Second, the number you came for is usually a different question, whether your salary kept pace, or what a house will cost in fifteen years.

So this one runs both directions. History mode uses real US Consumer Price Index data, every year from 1913 to 2025, any year to any year (forward, backward, or between two old years, not just against today). It sets the average annual rate right next to the cumulative jump so you can't misread one for the other, draws the value over time, and lists every year in a table. Forecast mode lets you pick a rate and project forward, and it shows the side the "future value" tools skip: what a fixed pile of cash actually buys after inflation eats at it.

Everything runs in your browser. Nothing you type is uploaded, no account, no limit. Share hands you a link that reopens the calculator with your exact figures, so you can keep a 2 percent and a 5 percent version side by side, and the amount you entered rides after the # in that link, the part a browser never sends to a server.

Two modes, one toggle at the top. Pick the one that matches your question.

Value across years (real CPI history):

1. Enter a dollar amount, an old salary or a childhood price.
2. Pick the year it's from. You can go back to 1913, or tap a quick-start button (1970, 1980, 2000).
3. Pick the year you want it expressed in. It defaults to the latest data year, but set it to anything, and you can run it backward to price today's money in the past.
4. Read the headline: the equivalent buying power, plus the total price change, the average inflation per year, and the multiplier prices grew by.
5. Underneath, a chart traces the value across every year in your range, and the table shows the CPI and equivalent for each one.

Forecast a rate (project forward):

1. Enter the amount you have today.
2. Enter how many years ahead to look.
3. Enter an annual inflation rate, or tap the 2, 3, or 5 percent shortcut.
4. You get two numbers. Future cost is what that amount will run later at your rate. Future buying power is what cash held that long will actually buy, stated in today's money.

Either way, Show the math prints the formula with your own numbers in it, Copy result grabs a plain-text summary, and Share copies a link that reopens the same calculation.

The result box shows two inflation figures on purpose, and mixing them up is the most common mistake with any inflation number you'll read.

Cumulative price change is the whole climb over the span. From 2000 to 2025 it's about 87 percent, and that's what turns $100 into $187. Average inflation per year is the smoothed yearly rate that compounds up to that same total, roughly 2.5 percent for that span. It is not 87 divided by 25 years, because inflation compounds, so each year's rise builds on the already higher base left by the previous year.

The trap is that the scary 87 percent and the sleepy 2.5 percent come from the identical data. Headlines quote whichever suits the story, the cumulative figure to worry you, the annual rate to reassure. Comparing eras, use the average annual rate, that's the apples-to-apples one. For the raw hit on a specific amount, use the cumulative change. A calculator that shows only one is how you walk away with the wrong instinct.

There's a second catch. The percent prices rise is not the percent your money loses. If prices go up 25 percent, your dollar doesn't shed 25 percent, it loses about 20, because the two are measured from opposite ends. History mode handles this, and forecast mode prints both figures so the gap is obvious.

The conversion is a ratio: your amount times (CPI in the target year divided by the original year), on data from the U.S. Bureau of Labor Statistics, which prices a fixed basket and pegs the 1982 to 1984 average at 100. Same method the government's own tool uses, this one just also gives you the yearly rate and every year in between.

Nobody knows what inflation will run over the next twenty years, so forecast mode makes you supply the rate instead of pretending it knows. The only real question is what to type.

For ordinary long-term planning, 2 to 3 percent is grounded. The Federal Reserve steers policy toward about 2 percent and the long-run US average sits near 3, so a college fund or a rough retirement target planned in that band is reasonable. My honest advice, don't grab a recent hot year and run with it. Living through 2022 makes 8 percent feel like the new normal, it isn't, one spike is not the trend. Run a high rate once to see the worst case, but don't plan around it.

The payoff is two numbers, and the second is the one most tools leave out. Future cost multiplies your amount up: at 3 percent, $1,000 today costs about $1,344 in ten years. Future buying power divides it down: that same $1,000 left sitting for ten years buys only what about $744 buys now, because cash quietly loses value while it waits. It's why a giant future number can be misleading. A million-dollar balance thirty years out has the buying power of about $412,000 in today's money, still a lot but nowhere near a million.

One honest limit. This tracks money sitting still, cash losing ground to prices, so it is not an investment calculator. If your money is invested, what matters is your real return, the growth minus inflation. This isolates the inflation half, so pair it with a savings or return tool for the rest.

Inflation isn't a steady drip. It has run hot, gone quiet, and a couple of times reversed outright. Here's the average annual CPI rate by decade, from the same data the tool uses.

Decade	Average inflation per year	What was going on
1920s	about -1.8%	Prices fell after the World War I spike
1930s	about -1.7%	Deflation through the Great Depression
1940s	about 5.6%	Wartime and postwar price surges
1950s	about 2.1%	Calm, steady growth
1960s	about 2.7%	Mild, creeping up late in the decade
1970s	about 7.8%	The great inflation, oil shocks
1980s	about 4.7%	Cooling from the 1970s peak
1990s	about 2.8%	A long, stable stretch
2000s	about 2.4%	Moderate, with a 2008 dip
2010s	about 1.7%	The quietest inflation in modern memory
2020s (through 2025)	about 4.5%	The post-pandemic surge

Over the full run from 1913 to 2025, prices rose about 3.2 percent a year on average, so the price level multiplied roughly 33 times. A 1913 dollar buys what about three cents did. The 2010s were about as calm as US inflation gets and the 1970s were brutal, but most stretches land between 2 and 4 percent, so reach for the extremes only with a reason.