Inflation Calculator
See how inflation changes the buying power and future cost of money over time.
Results update as you type.
About this calculator
Inflation erodes what money can buy: a fixed amount buys a little less each year. This calculator projects both the future cost of something priced today and the shrinking buying power of a fixed sum, using a constant annual inflation rate compounded over the period you choose.
It works both directions from the same rate. Future cost = amount × (1 + rate)^years, while future buying power = amount ÷ (1 + rate)^years. For example, at 3% inflation over 10 years, something that costs 1,000 today will cost about 1,344, and a 1,000 note kept under the mattress will buy only about 744 worth of today’s goods — a 25.6% loss of purchasing power even though the number on the note never changed.
Use it to see how prices creep up over a decade, to understand why cash loses value if it is not earning at least the inflation rate, or to translate an old price or salary into today’s money. For planning, enter the average rate you expect across the whole period rather than any single year’s figure.
Frequently asked questions
How does the inflation calculation work?
Future cost = amount × (1 + rate)^years, so something that costs 1,000 today costs about 1,344 after 10 years at 3%. Buying power works the other way: amount ÷ (1 + rate)^years, so 1,000 will only buy about 744 worth of today’s goods.
Where do I find the inflation rate to use?
Use your country’s consumer price index (CPI) figure — often around 2–3% in the long run for developed economies. For planning, enter the average rate you expect over the whole period, not a single year’s spike.
What is the difference between inflation and buying power?
They are two sides of one coin. Inflation is how much prices rise, so the future cost of goods goes up; buying power is how much a fixed sum can purchase, so it goes down by the same factor. If prices rise 34%, the same money buys about 25% less.
How can I protect my money from inflation?
Hold money where it earns at least the inflation rate — high-yield savings, inflation-linked bonds, or diversified investments — rather than as idle cash. What matters is your real return, the nominal return minus inflation; if that is negative, you are quietly losing purchasing power.
What is a normal rate of inflation?
Many developed-economy central banks target around 2% a year, and long-run averages often sit near 2–3%. Rates spike higher during supply shocks and can turn negative (deflation) in downturns, so use a long-term average for multi-year planning.
How much will prices double at a given inflation rate?
A quick estimate is the rule of 70: divide 70 by the inflation rate to get the years to double. At 3% a year prices double in roughly 23 years; at 7% in about 10. The calculator’s future-cost figure shows the exact multiple for your inputs.
API — use this calculator from code
Call this calculator as a free JSON endpoint — no key required. Send the field values below as query parameters or JSON. Read the full API docs →
Endpoint
GET https://calculator.free/api/v1/inflation/curl
curl "https://calculator.free/api/v1/inflation/?amount=1000&rate=3&years=10"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/inflation/?" + new URLSearchParams({
"amount": "1000",
"rate": "3",
"years": "10"
}));
const data = await r.json();
console.log(data.results);Results are estimates for general guidance only, not financial, medical or tax advice.