General
Inflation Calculator
See what an amount of money will be worth in the future at an assumed inflation rate, or how much you'd need to match today's purchasing power.
Purchasing power in the future
$5,537
what this amount, held as cash, would be worth in today's money
Future cost equivalent
$18,061
to buy what this buys today
Cumulative inflation
80.61%
Purchasing power lost
44.63%
At an assumed 3.0% annual inflation rate, something that costs $10,000 today would cost approximately $18,061 in 20 years — a cumulative 80.61% increase.
Looked at the other way, $10,000 left as cash for 20 years would have the purchasing power of only about $5,537 in today's money — a 44.63% loss of purchasing power.
Both figures are estimates based on the inflation rate you assume, not a prediction of actual future inflation, which is unknowable in advance.
Purchasing power over time
Your numbers
See how the inflation rate changes the result
Same amount and time horizon, three different assumed inflation rates — not predictions, just different assumptions.
2% inflation
$6,730
purchasing power remaining
3% inflation
$5,537
purchasing power remaining
5% inflation
$3,769
purchasing power remaining
The formula
Future Cost = Amount × (1 + Inflation Rate) ^ Years
The same formula runs in reverse for purchasing power: dividing instead of multiplying by (1 + inflation rate) ^ years converts a present amount into what it would be worth, in today's terms, after that many years of erosion.
How to read it
Inflation is easy to underestimate because it works quietly. A 3% annual rate barely registers year to year, but compounded over two or three decades it can cut purchasing power by half or more — the same compounding math that grows an investment also erodes cash that just sits still.
This is why "how much money will I have" and "how much will that money actually buy" are different questions. A savings account or a mattress full of cash can preserve the nominal amount perfectly while still losing most of its real value over a long enough horizon.
There's no way to know future inflation in advance, which is why the comparison below holds your amount and time horizon fixed and only changes the assumed rate — small differences in that one assumption compound into large differences over 20 or 30 years.
Frequently asked
What does 'purchasing power' mean here?+
It's what a given amount of money can actually buy, adjusted for rising prices. $10,000 held as cash doesn't shrink in nominal terms, but if prices rise 3% a year, it buys less and less each year — that shrinking buying power is what this calculator measures.
What's the difference between 'future cost equivalent' and 'purchasing power lost'?+
They're the same relationship viewed from two directions. Future cost equivalent asks: what would I need to spend in the future to buy what this amount buys today? Purchasing power lost asks the reverse: if I just hold this amount as cash, what will it be worth in today's terms? Both come from the same inflation assumption.
Can this calculator predict future inflation?+
No. It applies whatever constant annual rate you enter, consistently, across the time horizon. Actual inflation varies year to year and cannot be known in advance — treat the rate you enter as an assumption you're testing, not a forecast, and try a few different rates using the comparison below.
How is this different from the compound interest calculator?+
Compound interest models money that's invested and growing. This calculator models the opposite scenario: money that isn't growing at all, just losing purchasing power to inflation. If you want to see inflation-adjusted results alongside investment growth, use the compound interest calculator's advanced options instead.
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View all →Educational tool, not advice. This calculator illustrates a standard formula using the numbers you enter. It does not account for your full financial picture, taxes, or local market conditions, and it is not a recommendation to buy, sell, or hold any asset. Speak with a licensed professional before making investment decisions.