Cumulative Inflation

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Calculate

Example: a year's monthly inflation rates, illustrative, in %. How much did prices rise over the year, and what is a value of 1,000 from the start worth today? Change the values to work out your own case.

Rates per period (%) In order, separated by spaces or commas. Value to adjust (optional) Blank: just the rate.

Step by step

What each term means

Cumulative Inflation (I): How much prices rose over the whole period, relative to the start.
Product of the Factors: Each rate becomes a factor: 0.5% becomes 1.005. The factors are multiplied, because each rise applies to prices that have already risen — it is interest on interest.
Minus 1: The product says by how much prices were multiplied; subtracting 1 leaves the rise. A factor of 1.045 is 4.5% inflation.