$18.50 in 1900 is worth $522.00 in 2015

Buying power of $18.50 in 1900

This chart shows a calculation of buying power equivalence for $18.50 in 1900 (price index tracking began in 1635).

For example, if you started with $18.50, you would need to end with $522.00 in order to "adjust" for inflation (sometimes refered to as "beating inflation").

When $18.50 is equivalent to $522.00 over time, that means that the "real value" of a single U.S. dollar decreases over time. In other words, a dollar will pay for fewer items at the store.

This effect explains how inflation erodes the value of a dollar over time. By calculating the value in 1900 dollars, the chart below shows how $18.50 is worth less over 115 years.

According to the Bureau of Labor Statistics, each of these USD amounts below is equal in terms of what it could buy at the time:

This conversion table shows various other 1900 amounts in 2015 dollars, based on the 2,721.63% change in prices:

Inflation by Country

Inflation can also vary widely by country. For comparison, in the UK £18.50 in 1900 would be equivalent to £2,051.09 in 2015, an absolute change of £2,032.59 and a cumulative change of 10,986.96%.

Compare these numbers to the US's overall absolute change of $503.50 and total percent change of 2,721.63%.

Inflation by Spending Category

CPI is the weighted combination of many categories of spending that are tracked by the government. Breaking down these categories helps explain the main drivers behind price changes.

This chart shows the average rate of inflation for select CPI categories between 1900 and 2015.

Compare these values to the overall average of 2.95% per year:

The graph below compares inflation in categories of goods over time. Click on a category such as "Food" to toggle it on or off:

For all these visualizations, it's important to note that not all categories may have been tracked since 1900. This table and charts use the earliest available data for each category.

How to calculate inflation rate for $18.50, 1900 to 2015

Our calculations use the following inflation rate formula to calculate the change in value between 1900 and 2015:

Then plug in historical CPI values. The U.S. CPI was 8.4 in the year 1900 and 237.017 in 2015:

$18.50 in 1900 has the same "purchasing power" or "buying power" as $522.00 in 2015.

To get the total inflation rate for the 115 years between 1900 and 2015, we use the following formula:

Plugging in the values to this equation, we get:

Comparison to S&P 500 Index

The average inflation rate of 2.95% has a compounding effect between 1900 and 2015. As noted above, this yearly inflation rate compounds to produce an overall price difference of 2,721.63% over 115 years.

To help put this inflation into perspective, if we had invested $18.50 in the S&P 500 index in 1900, our investment would be nominally worth approximately $733,212.82 in 2015. This is a return on investment of 3,963,212.55%, with an absolute return of $733,194.32 on top of the original $18.50.

These numbers are not inflation adjusted, so they are considered nominal. In order to evaluate the real return on our investment, we must calculate the return with inflation taken into account.

The compounding effect of inflation would account for 0.00% of returns ($0.00) during this period. This means the inflation-adjusted real return of our $18.50 investment is $0.00. You may also want to account for capital gains tax, which would take your real return down to around $0 for most people.

Information displayed above may differ slightly from other S&P 500 calculators. Minor discrepancies can occur because we use the latest CPI data for inflation, annualized inflation numbers for previous years, and we compute S&P price and dividends from January of 1900 to latest available data for 2015 using average monthly close price.

For more details on the S&P 500 between 1900 and 2015, see the stock market returns calculator.

Data source & citation

Raw data for these calculations comes from the Bureau of Labor Statistics' Consumer Price Index (CPI), established in 1913. Price index data from 1774 to 1912 is sourced from a historical study conducted by political science professor Robert Sahr at Oregon State University and from the American Antiquarian Society. Price index data from 1634 to 1773 is from the American Antiquarian Society, using British pound equivalents.

» Read more about inflation and investment.