$20 in 2021 is worth $2.86 in 1970

Buying power of $20 in 1970

This chart shows a calculation of buying power equivalence for $20 in 1970 (price index tracking began in 1635).

For example, if you started with $20, you would need to end with $2.86 in order to "adjust" for inflation (sometimes refered to as "beating inflation").

When $20 is equivalent to $2.86 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 1970 dollars, the chart below shows how $20 is worth less over 51 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 1970 amounts in 2021 dollars, based on the -85.68% change in prices:

Inflation by City

Inflation can vary widely by city, even within the United States. Here's how some cities fared in 2021 to 1970 (figures shown are purchasing power equivalents of $20):

• San Francisco, California: 4.22% average rate, $20 → $164.89, cumulative change of 724.47%
• Seattle, Washington: 4.14% average rate, $20 → $158.29, cumulative change of 691.47%
• Boston, Massachusetts: 3.98% average rate, $20 → $146.62, cumulative change of 633.10%
• New York: 3.92% average rate, $20 → $142.07, cumulative change of 610.33%
• Atlanta, Georgia: 3.83% average rate, $20 → $135.74, cumulative change of 578.72%
• Dallas-Fort Worth, Texas: 3.80% average rate, $20 → $134.14, cumulative change of 570.70%
• Philadelphia, Pennsylvania: 3.77% average rate, $20 → $131.91, cumulative change of 559.56%
• Houston, Texas: 3.76% average rate, $20 → $131.52, cumulative change of 557.60%
• Chicago, Illinois: 3.75% average rate, $20 → $130.62, cumulative change of 553.09%
• Detroit, Michigan: 3.66% average rate, $20 → $125.26, cumulative change of 526.30%

San Francisco, California experienced the highest rate of inflation during the 51 years between 1970 and 2021 (4.22%).

Detroit, Michigan experienced the lowest rate of inflation during the 51 years between 1970 and 2021 (3.66%).

Note that some locations showing 0% inflation may have not yet reported latest data.

Inflation by Country

Inflation can also vary widely by country. For comparison, in the UK £20.00 in 2021 would be equivalent to £1.24 in 1970, an absolute change of £-18.76 and a cumulative change of -93.81%.

In Canada, CA$20.00 in 2021 would be equivalent to CA$2.87 in 1970, an absolute change of CA$-17.13 and a cumulative change of -85.64%.

Compare these numbers to the US's overall absolute change of $-17.14 and total percent change of -85.68%.

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 2021 and 1970.

Compare these values to the overall average of 3.88% 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 2021. This table and charts use the earliest available data for each category.

How to calculate inflation rate for $20, 1970 to 2021

Our calculations use the following inflation rate formula to calculate the change in value between 1970 and 2021:

Then plug in historical CPI values. The U.S. CPI was 270.97016666667 in the year 2021 and 38.8 in 1970:

$20 in 2021 has the same "purchasing power" or "buying power" as $2.86 in 1970.

To get the total inflation rate for the 51 years between 1970 and 2021, we use the following formula:

Plugging in the values to this equation, we get:

Alternate Measurements of Inflation

There are multiple ways to measure inflation. Published rates of inflation will vary depending on methodology. The Consumer Price Index, used above, is the most common standard used globally.

Alternative measurements are sometimes used based on context and economic/political circumstances. Below are a few examples of alternative measurements.

Personal Consumption Expenditures (PCE) Inflation

The PCE Price Index is the U.S. Federal Reserve's preferred measure of inflation, compiled by the Bureau of Economic Analysis. It measures the change in prices of goods and services purchased by consumers.

The PCE Price Index changed by 3.40% per year on average between 2021 and 1970. The total PCE inflation between these dates was 451.32%. In 2021, PCE inflation was 4.67%.

This means that the PCE Index equates $20 in 2021 with $110.26 in 1970, a difference of $90.26. Compare this to the standard CPI measurement, which equates $20 with $2.86. The PCE measured 537.00% inflation compared to standard CPI.

For more information on the difference between PCE and CPI, see this analysis provided by the Bureau of Labor Statistics.

Core Inflation

Also of note is the Core CPI, which uses the standard CPI but omits the more volatile categories of food and energy.

Core inflation averaged 3.83% per year between 2021 and 1970 (vs all-CPI inflation of 3.88%), for an inflation total of 579.16%. In 2021, core inflation was 6.25%.

When using the core inflation measurement, $20 in 2021 is equivalent in buying power to $135.83 in 1970, a difference of $115.83. Recall that the converted amount is $2.86 when all items including food and energy are measured.

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.