How to use the inflation calculator
Start with the amount and dates you want to compare. Then choose one annual rate or enter a rate for each calendar year in the range. The result shows cumulative inflation, the equivalent value at the end date, and the formula used.
- Enter a value greater than 0 in Starting amount ($), then choose Start date and End date. End date must be after Start date.
- Select Single annual rate or Year-by-year rate series.
- For one rate, enter Annual inflation rate (%). For a series, click Build year fields from dates and fill in each generated year field.
- Enter Ending nominal amount ($) when you want Nominal change and Real change (inflation-adjusted).
- Click Calculate. After the result appears, use Copy result, Download result (.txt), or Reset.
Calculate purchasing power between dates
Single annual rate applies one percentage across the date range. The calculator measures the period as days between the dates divided by 365.25, then compounds the rate for that period. A negative rate is accepted for deflation when it is above -100%.
Starting amount ($): $10,000
Start date: 2015-01-01
End date: 2026-01-01
Annual inflation rate (%): 3.2
Equivalent value at end date: $14,141.19
Cumulative inflation: 41.41%Use year-by-year inflation rates
Select Year-by-year rate series when the rate changes by calendar year. Enter valid dates, then click Build year fields from dates. The calculator creates one field for every year touched by the range. If you change either date, build the fields again. Each rate applies to that year's fraction of the range, and the year factors are multiplied together.
Read the inflation-adjusted value
The result shows Cumulative inflation, Equivalent value at end date, and Years elapsed. Money values display in USD. When you enter Ending nominal amount ($), it also shows Nominal change and Real change (inflation-adjusted).
For one rate, the calculator uses Cumulative factor = (1 + rate / 100)^years, then Equivalent value = Starting amount × Cumulative factor. In series mode, it multiplies one fractional-year factor for each calendar year.
What this inflation calculator does not look up
You provide every rate. The calculator does not fetch live CPI, official inflation indexes, or government rates. It also does not convert currencies or model regional price differences. The calculation runs in your browser, and the entered amount, dates, and rates are not sent to a calculation service.
- Starting amount ($) must be greater than 0.
- Ending nominal amount ($), when used, must be 0 or greater.
- Both dates must be valid, and End date must be after Start date.
- Rates at or below
-100%are rejected.
Examples of using the inflation calculator
To compare an old purchase amount with a later value, enter the amount, dates, and a rate assumption. The result gives the equivalent value at the end date.
For a date range with changing rates, select Year-by-year rate series. Build the fields, enter each year's rate, and use the year-by-year breakdown in the result.
For a pay or pricing review, enter Ending nominal amount ($). The result places the stated change beside the inflation-adjusted change.
Choose the right financial calculator
Use the financial calculators category for other money calculations. The CAGR Calculator calculates annualized growth from a starting value, ending value, and two dates. The Future Value Calculator handles a lump sum plus regular contributions with an interest rate and compounding frequency. The APY Calculator calculates effective annual yield from a nominal rate and compounding frequency.
Frequently asked questions
Does the inflation calculator use official CPI data?
No. It uses only the rate or rates you enter and does not fetch live CPI, official indexes, or government inflation figures.
How do I calculate an inflation-adjusted value between two dates?
Enter Starting amount ($), Start date, End date, and a rate, then click Calculate. The result multiplies your starting amount by the cumulative factor.
How do year-by-year inflation rates work?
Select Year-by-year rate series, click Build year fields from dates, and enter a rate for every generated year. Each rate is applied to that year's fraction of the date range.
What are real and nominal change?
Nominal change compares the starting amount with Ending nominal amount ($). Real change adjusts that comparison by the cumulative inflation factor, and both values appear only when the ending amount is entered.