Inflation Calculator
Pick a direction, set your amount, rate, and years — the result updates as you type, and the link in your address bar always reflects your numbers.
How this calculator works
Inflation is compound growth applied to prices. This tool models it with a single constant annual rate. In future cost mode it grows the amount forward: A·(1 + r)n — what a basket costing your amount today would cost after n years. In purchasing power mode it does the reverse: A / (1 + r)n — what your amount, left as cash, will actually buy in today's terms. Real inflation varies year to year (that's what the CPI measures), so treat this as a scenario tool: try the long-run ~3% average, then a pessimistic rate, and see how wide the range is.
Worked example
Take $1,000 at 3% for 10 years. In future-cost mode: buying what $1,000 buys today would cost about $1,343.92 in 10 years. Flip to purchasing-power mode and the same assumptions say $1,000 kept as cash will only buy what $744.09 buys today — a quarter of its usefulness gone without the balance ever changing. Stretch to 30 years and the future cost climbs to about $2,427.26.
Frequently asked questions
What inflation rate should I use?
The long-run US average is roughly 3% a year, which is why it's the default here. But recent history shows how much it moves: some years have run near zero and others well above 5%. For short horizons, recent readings matter more; for multi-decade planning, a long-run average is the usual starting point. This tool lets you try any rate instantly.
Is this the same as the CPI?
No, and the difference is worth understanding. CPI (the Consumer Price Index) is a measured statistic — actual recorded price changes for a basket of goods, which vary every year. This calculator applies one constant rate for every year, which makes it a clean what-if model rather than a historical lookup. Use it to explore scenarios, not to convert exact historical dollar amounts.
How does inflation affect savings versus debt?
It cuts both ways. Cash loses purchasing power: at 3%, $1,000 buys only what about $744.09 buys today after 10 years. But a fixed-rate debt is repaid in those same cheaper dollars, so inflation quietly lightens its real burden. That's why the gap between your savings rate and inflation — the real rate — matters more than either number alone.
Why do small rates add up so much over decades?
Because inflation compounds — each year's increase applies to already-increased prices. At just 3%, what costs $1,000 today costs about $1,343.92 in 10 years but roughly $2,427.26 in 30 years. The rate never changed; the doubling comes purely from compounding. It's the same math as compound interest, working against your cash instead of for it.