Enter an amount, a starting and ending year, and an assumed annual inflation rate to see its future or past value and the cumulative inflation over that period.
This calculator applies one constant inflation rate you choose across every year in the period. Actual inflation, measured by the Consumer Price Index (CPI), varies year to year — some years run well above average, others near zero or even negative — so a real historical adjustment would apply the actual CPI reading for each specific year rather than one smoothed average rate.
US inflation has averaged roughly 3% a year over long historical stretches, which is why that's the default here, but actual annual rates have ranged from near 0% to over 9% depending on the period. There's no single "correct" number to use for a future projection — try a few different rates to see how sensitive your result is to the assumption.
Each year's price increase applies to the already-higher price level left over from the prior year, not back to the original starting amount — exactly the same mechanism as compound interest. Over long periods this compounding is why even a modest annual rate erodes purchasing power far more than simply multiplying the rate by the number of years would suggest.
Inflation steadily reduces the real purchasing power of a fixed savings balance, so a nest egg that looks sufficient today may buy noticeably less by the time you actually retire decades from now. Use the Retirement Calculator to model savings growth alongside your expected retirement spending needs.
Worked example: $10,000 in 2015 dollars, projected forward to 2025 at an assumed 3% annual inflation rate, comes to 10,000 × 1.0310 ≈ $13,439.16 — cumulative inflation of about 34.39% over that 10-year span.
Want to see how inflation interacts with long-term growth? Try the Retirement Calculator or the Savings Calculator.