Cumulative Inflation Calculator

Calculate the total percentage of price inflation between two dates.

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Using the Inflation Calculator below you can determine the cumulative inflation (in percent) ranging from 1913- Present. This calculator uses the Consumer Price Index published by the U.S. Bureau of Labor Statistics which is the most closely watched indicator for inflation in the U.S. It can be considered the "government's key inflation barometer". Using the Inflation Rate Calculator will give you the cumulative inflation between any two months. Please read the following instructions carefully. It does make a difference in understanding how the Inflation calculator works and ensuring that you get the right answer. To start select the starting month and year and the ending month and year and then click the "Calculate Inflation Rate" button to see your inflation calculation.

Remember the data is released mid-month for the prior month and is two weeks old by the time it is released by the Bureau of Labor Statistics. So depending on what time of month it is, you can only get data up through last month or even the previous month. (Early in the month you will have to go two months prior, late in the month it will be the previous month. CPI Index Release Dates

Once you hit the "Calculate Inflation" Button the result will appear in an empty box in the bottom of the inflation calculator.

Cumulative Inflation Calculator

  Starting Date Ending Date
To Calculate a whole year use the same month, i.e., Jan. 2010 - Jan. 2011 gives a full year.
Jan - Dec only gives 11 months. (Do not select current month)

Cumulative Inflation Results

Note: This U.S. Inflation Rate Calculator gives you the percentage of increase in prices over a period. For example from January 2005 - January 2006 prices increased 3.99% therefore something that cost $1 in January 2005 would cost $1 + (inflation rate) in January 2006. So in this case it would be $1+($1 x .0399)= $1.0399 or $1.04

To compare the cost of living in two cities use this Cost of Living calculator.

Although this seems obvious for one year when the inflation rate gets larger (above 100%) it is not so intuitive.

From December 1957 through December 2007 the Inflation Rate Calculator will tell you that inflation was 639.56%.

If we plug the calculator results into the above formula we find that something that cost $1 in December 1957 would cost $1+ ($1 x 6.3956)=$7.40

Remember the result is in percent.

To calculate its decimal equivalent you need to move the decimal point two places to the left. So 639.56% = 6.3956 in decimals.  

Once you know the inflation rate from the calculator above, you might want to know how much something would cost after increasing by that amount of inflation. To calculate that simply plug the starting amount (without commas or decimals) into this calculator. Then put in the inflation rate you calculated from above and click calculate.

Calculate how much it would cost after Inflation

Starting Amount $
(do not enter commas)
Rate of inflation X %

How much it would cost after Inflation:

If you would prefer to skip this step (or don't care about a specific monthly number) you can calculate the difference in costs based on annual averages using the Bureau of Labor Statistics Inflation Calculator.

Note: The results from these two calculations will differ slightly because one is based on an exact month (January) and the other is based on the average annual index (which should be close to the results if you used June or July as your month of choice.

Is your salary keeping up with inflation? What you need next year just to keep up.  Use our Salary Inflation Calculator

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