Inflation Calculator
See what today's prices will look like in the future — and what today's money will actually be worth then.
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Future cost of today's $100 item
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Estimate only — real inflation varies year to year.
How it works
Inflation compounds just like interest, but working against your money. Two formulas cover both directions:
Where PV is today's amount, i the annual inflation rate (as a decimal), and n the number of years. At 3% inflation, prices double roughly every 24 years — the classic "rule of 72" (72 ÷ 3 ≈ 24).
Frequently asked questions
What is inflation, exactly?
Inflation is the general rise in prices over time, which means each dollar buys less than it used to. Central banks usually target around 2 percent per year, and higher inflation erodes the value of idle savings faster.
What inflation rate should I use?
For US planning, 2 to 3 percent is a common long-term assumption. You can also use the historical average of about 3 percent over the last century, or test a higher rate to stress-test your plans.
What is the difference between future cost and purchasing power?
They are two sides of the same coin. Future cost shows what today's $100 item will cost later, while purchasing power shows what today's $100 will be able to buy later. One multiplies by (1 + inflation)^years, the other divides by it.
Is inflation always bad?
Not necessarily. Mild inflation usually comes with wage growth and a growing economy. It mainly hurts cash sitting still, which is why long-term money is usually invested rather than kept in a drawer.