Inflation Calculator
You supply the inflation rate — this tool keeps no price index and makes no forecast. It shows what today's costs become, and what future money shrinks to, at the rate you choose.
Your rate, your answer — no index consulted
This tool deliberately keeps no CPI dataset and makes no forecast: you supply the inflation rate, and it performs the two translations that matter — what today's amount will cost in the future, and what a future amount is worth in today's spending power.
Future cost = amount × (1 + inflation)years · Today's value of a future amount = amount ÷ (1 + inflation)years
Example: at 3% inflation, $1,000 of today's spending costs $1,343.92 in 10 years — and $1,000 received in 10 years spends like $744.09 today. At 5%, the 10-year cost is $1,628.89. Two points of rate assumption, $285 of difference: the input is the argument.
Personal inflation is not headline inflation
The official index averages a national basket; your basket — heavy on rent, tuition or healthcare — can inflate much faster. Retirees and parents often live a point or two above the headline. Enter the rate your life actually experiences.
How this is calculated
Pure compounding at the rate you enter: forward for costs, inverted for purchasing power. Purchasing-power loss = 1 − (1 + r)^(−years). Historical price-index lookup and forecasting are excluded by design (see the page's stance: forward math only), so no stale table can quietly date the result.
Frequently asked questions
Why doesn't this use real historical inflation?
Because the useful question is forward — 'what will this cost, what will that be worth' — and historical tables would date instantly while inviting false precision about the future. The rate is your planning assumption, made explicit.
How fast does money halve in value?
By the Rule of 72: at 3% inflation purchasing power halves in about 24 years; at 5%, about 14. Cash 'under the mattress' is a slow short position against the currency.
Should my investment return beat inflation by some margin?
That margin is your real return: an 7% nominal return at 3% inflation is roughly a 3.9% real return ((1.07 ÷ 1.03) − 1). Retirement plans built on nominal returns alone overstate their purchasing power.
Is inflation the same everywhere in a country?
Officially it is one index; lived, it varies by region and household. Housing-weighted lives in expensive cities have run hotter than the national figure for long stretches.
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