$3,906 in 2015 has the same purchasing power as $4,138.20 in 2018. Over the 3 years this is a change of $232.20.

The average inflation rate of the dollar between 2015 and 2018 was 1.49% per year. The cumulative price increase of the dollar over this time was 5.94%.

## The value of $3,906 from 2015 to 2018

So what does this data mean? It means that the prices in 2018 are 41.38 higher than the average prices since 2015. A dollar in 2018 can buy 94.39% of what it could buy in 2015.

These inflation figures use the Bureau of Labor Statistics (BLS) consumer price index to calculate the value of $3,906 between 2015 and 2018.

The inflation rate for 2015 was 0.12%, while the inflation rate for 2018 was 2.44%. The 2018 inflation rate is higher than the average inflation rate of 2.14% per year between 2018 and 2021.

## USD Inflation Since 1913

The chart below shows the inflation rate from 1913 when the Bureau of Labor Statistics' Consumer Price Index (CPI) was first established.

## The Buying Power of $3,906 in 2015

We can look at the buying power equivalent for $3,906 in 2015 to see how much you would need to adjust for in order to beat inflation. For 2015 to 2018, if you started with $3,906 in 2015, you would need to have $4,138.20 in 2015 to keep up with inflation rates.

So if we are saying that $3,906 is equivalent to $4,138.20 over time, you can see the core concept of inflation in action. The "real value" of a single dollar decreases over time. It will pay for fewer items at the store than it did previously.

In the chart below you can see how the value of the dollar is worth less over 3 years.

## Value of $3,906 Over Time

In the table below we can see the value of the US Dollar over time. According to the BLS, each of these amounts are equivalent in terms of what that amount could purchase at the time.

## US Dollar Inflation Conversion

If you're interested to see the effect of inflation on various 1950 amounts, the table below shows how much each amount would be worth today based on the price increase of 5.94%.

## Calculate Inflation Rate for $3,906 from 2015 to 2018

To calculate the inflation rate of $3,906 from 2015 to 2018, we use the following formula:

$$\dfrac{ 2015\; USD\; value \times CPI\; in\; 2018 }{ CPI\; in\; 2015 } = 2018\; USD\; value $$

We then replace the variables with the historical CPI values. The CPI in 2015 was 237.017 and 251.107 in 2018.

$$\dfrac{ \$3,906 \times 251.107 }{ 237.017 } = \text{ \$4,138.20 } $$

$3,906 in 2015 has the same purchasing power as $4,138.20 in 2018.

To work out the total inflation rate for the 3 years between 2015 and 2018, we can use a different formula:

$$ \dfrac{\text{CPI in 2018 } - \text{ CPI in 2015 } }{\text{CPI in 2015 }} \times 100 = \text{Cumulative rate for 3 years} $$

Again, we can replace those variables with the correct Consumer Price Index values to work out the cumulativate rate:

$$ \dfrac{\text{ 251.107 } - \text{ 237.017 } }{\text{ 237.017 }} \times 100 = \text{ 5.94\% } $$

## Inflation Rate Definition

The inflation rate is the percentage increase in the average level of prices of a basket of selected goods over time. It indicates a decrease in the purchasing power of currency and results in an increased consumer price index (CPI). Put simply, the inflation rate is the rate at which the general prices of consumer goods increases when the currency purchase power is falling.

The most common cause of inflation is an increase in the money supply, though it can be caused by many different circumstances and events. The value of the floating currency starts to decline when it becomes abundant. What this means is that the currency is not as scarce and, as a result, not as valuable.

By comparing a list of standard products (the CPI), the change in price over time will be measured by the inflation rate. The prices of products such as milk, bread, and gas will be tracked over time after they are grouped together. Inflation shows that the money used to buy these products is not worth as much as it used to be when there is an increase in these products’ prices over time.

The inflation rate is basically the rate at which money loses its value when compared to the basket of selected goods – which is a fixed set of consumer products and services that are valued on an annual basis.