An inflation calculator for one lump sum. It shows the later amount with the same buying power, and what a fixed nominal sum is worth in today’s money, at an annual rate you choose.
How inflation erodes purchasing power
The figures are an educational estimate, not financial advice. See the disclaimer.
This calculator applies one annual inflation rate for a whole number of years. It does not download a price index and it does not forecast inflation. The default rate is an illustration.
Constant annual rate, annual compounding, and a rate you supply. No fees, tax, or investment return.
i = rate% / 100
F = (1 + i)^n
future nominal = A × F
real value = A / F
Take 10,000 at an illustrative 3% for 10 years. The factor is about 1.343916. The amount needed later for the same buying power is 13,439.16. A sum that stays at 10,000 has a real value of 7,440.94. Cumulative inflation is 34.39% and purchasing power retained is 74.41%. The year labels 2016 to 2026 use the same 10-year span.
| Amount | Rate | Years | Needed later | Real value |
|---|---|---|---|---|
| 10,000 | 3% | 10 | 13,439.16 | 7,440.94 |
| 100 | 10% | 2 | 121.00 | 82.64 |
| 500 | 6.5% | 1 | 532.50 | 469.48 |
| 10,000 | −2% | 5 | 9,039.21 | 11,062.92 |
Purchasing-power maths follow BLS CPI education (index ratios). With a constant annual rate, the factor is (1 + i)^n.
The factor F is one plus the decimal rate, raised to the number of whole years. The amount needed later equals today’s amount times F. The real value of a nominally fixed sum is that amount divided by F. Purchasing power retained is 100 divided by F.
This calculator does not download a consumer price index and does not forecast prices. One rate cannot describe every place or every year. The default of 3% is only an illustration so the form has a starting point. Replace it with the assumption you want to test. The figures then follow the rate you type.
Future nominal is the later amount that buys what today’s amount buys now, after prices change by the factor F. Real value runs the other way. It is a cash pile that stays at the same nominal amount, measured in today’s buying power after those years. A positive rate lifts future nominal and lowers real value.
No. BLS purchasing-power education uses a ratio of two index readings. With a constant annual rate, that ratio equals one plus the decimal rate, raised to the number of years. You enter the rate and the years yourself. This page does not download an index, and the default 3% is not an official figure.
No. It is an educational estimate from the compound formula on this page. Fees, tax, and investment return are left out. For a balance that earns interest, use the compound interest calculator. A constant rate is an assumption you choose, not a prediction of future prices.