# Inflation Calculator

With this US Inflation Calculator you are able to find out how the value of the USD has changed over the years.

## How the US Inflation Calculator Works

When using the US Inflation Calculator, you are able to measure how the value of the USD has changed over the years. The calculator uses data which is taken from the CPI-U (Consumer Price Index for All Urban Consumers), a database which is provided by the Bureau of Labor Statistics. This database contains information which has been tracked from the year 1913. Below is an example to demonstrate how the calculator calculates the US inflation.

### An example

If you were to spend a total of $100 at a shop in August of 2015, how much would that equate to if you were to purchase the same goods in August of 2016?

- August 2015 CPI-U index = 238.316 (CPI 1)
- August 2016 CPI-U index = 240.849 (CPI 2)
- The formula below will be used,
- August 2015 USD Value x (CPI 2 / CPI 1) = August 2016 Value
- If we implement the actual values of these,
- $100 x (240.849 / 238.316) = $100 x 1.0106 = $101.062
- Price in August 2016 = $101.062

### Calculating Annual Inflation Rates

- In this example, to calculate the inflation rate for August 2016, take its CPI of "240.849" and subtract from it last year's August 2015 CPI of "238.316".
- The result is "2.533". Divide this number by the August 2015 CPI and then multiply that by 100 and add a % sign.
- (2.533 / 238.316) x 100%
- The result is August's annual inflation rate of 1.062%.

### The US inflation calculator uses the following formulae:

To revalue a sum of money between two periods in time adjusting to the CPI use the following formula:

*Sum of money ($) times (later date index divided by earlier date index)*

e.g: $100 x (240.849 [2016]) /238.316 [2015] = $101.062

To calculate a percentage change between any two months adjusting to the CPI use the following formula:

*(later date index minus earlier date index divided by earlier date index) times 100*

e.g: (240.849 [2016] - 238.316 [2015]) / 238.316 [2015] x 100 = 1.062%