Inflation Calculator (Purchasing Power)
Calculate what an amount of money in one year is worth in today's dollars, using a configurable inflation rate.
What this calculates
Inflation quietly erodes purchasing power year after year. A $100 bill that bought a week of groceries in 1990 doesn't go nearly as far today. This calculator translates any amount between two years using a configurable annual rate so you can see what money was — or will be — worth in today's terms.
Formula & how it works
Future value = present × (1 + rate)^years. Present value = future ÷ (1 + rate)^years. Rate is expressed as an annual decimal (e.g., 3 % = 0.03). For multi-decade comparisons, use a long-run average rate (US has averaged ~3 % since 1913, but recent years have been higher).
Worked example
$100 in 1990 at 3 % average inflation. After 36 years: 100 × (1.03)^36 ≈ $290. So $100 from 1990 has the buying power of about $290 today. Reverse: $1,000 today would have felt like $345 in 1990 dollars.
Frequently asked questions
What inflation rate should I use?
US long-run average is about 3 %. The last decade ran 2–4 %, with a 2022 spike to 8 %. Use 3 % for general long-term math; bump to 4 % for the current decade.
Does this work for any country?
Yes — change the rate to your country's average. Argentina, Turkey, and others have run 30–80 % in recent years; Japan often near 0 %. The math is the same.
Why doesn't this match CPI exactly?
We use a constant rate. Real CPI varies year-to-year. For precise historical conversions, use the BLS CPI Inflation Calculator or look up CPI-U for each year.
Is inflation always bad?
Mild inflation (2–3 %) signals a growing economy and encourages spending/investment. Deflation is generally worse — it discourages activity. Runaway inflation (10 %+) hurts savers most.