Inflation Calculator

Inflation Calculator shows what inflation does to a sum of money: both what an old amount is worth in today's terms, and what you would need today to buy what that amount once bought.

Inflation compounds, which is why it does more damage than people expect. At 5% a year, prices do not rise 50% in ten years; they rise about 63%, because each year's increase applies to the already-increased level. Over twenty-five years at the same rate, money loses around 70% of its buying power. Those are the numbers that make a long-term savings plan look different.

The two directions are worth keeping distinct. Looking backwards asks what an old salary or price is equivalent to now. Looking forwards asks what today's money will be worth later, which is the calculation that matters for anything you are saving towards. The calculator does both, and labels which is which.

You supply the rate. There is no live price index here, because that would need a server and a data feed, and a figure quietly going out of date is worse than one you chose deliberately. For a historical period, look up the average rate for your country and that span; for a forward projection, the rate is an assumption and the answer is only as good as it.

Everything is worked out inside your browser. Nothing you enter is uploaded, logged or stored, which matters for the financial calculators in particular: the figures you put into them are nobody else's business.

• Works forwards and backwards in time
• Buying power expressed as a percentage, not just an amount
• Year-by-year table of the declining value
• Cumulative inflation over the whole period
• Any currency and any rate, including deflation
• No live data feed, so nothing silently goes stale
• Runs in your browser

The inflation calculator is used by writers, developers, students, marketers and anyone else who needs the job done once without installing software. Common cases include:

• Working out what an old salary is worth today
• Seeing what a savings target will really buy in fifteen years
• Checking whether a pay rise keeps up with prices
• Understanding a historical price you have read about
• Setting a retirement figure in realistic terms