How Inflation Erodes Your Money, With Charts and Examples

Inflation is the slow rise in prices that makes each dollar buy a little less every year. It is easy to ignore because it happens gradually, but over a working life it changes how much your savings are really worth. This guide explains how inflation is measured, what it did to a dollar over the last few decades, and how to judge returns after inflation.

How inflation is measured

In the United States the Bureau of Labor Statistics publishes the CPI each month. It follows the prices of more than 200 categories of goods and services, from food and rent to medical care and transport, weighted by how much households actually spend on each. The most-quoted version is the CPI-U, which covers urban consumers. The index is set to 100 in a base period (1982–84), so a value of 321.9 means the same basket costs about 3.2 times what it did then.

The inflation rate is the percentage change in the index. To convert an amount between two dates, multiply it by the ratio of the two index values:

Our Inflation Calculator does this with US data back to 1913.

Inflation does not move in a straight line

Over 2000 to 2025 US inflation averaged about 2.6% a year, but individual years varied a lot, from -0.4% in 2009 to 8.0% in 2022.

View the yearly inflation figures

Year	CPI-U annual average	Inflation
2000	172.2	3.4%
2005	195.3	3.4%
2010	218.1	1.6%
2015	237.0	0.1%
2020	258.8	1.2%
2022	292.7	8.0%
2025	321.9	2.6%

The long-run effect: buying power

The effect that matters for retirement is cumulative. At 3% inflation, $100 of buying power shrinks to about $55 after 20 years and about $41 after 30. The rule of 72 gives a quick estimate: prices double in roughly 72 ÷ inflation rate years, which is about 24 years at 3% and 36 years at 2%.

Real return: what your savings actually earn

A savings account that pays 4% sounds good, but if prices rise 3% you are really only ahead by about one percent. The real return is the nominal return adjusted for inflation:

This is why cash held for decades tends to lose value in real terms, and why long-term savings are usually invested in assets that have historically beaten inflation over time, even though those assets rise and fall in the short run. See the compound interest guide for how that growth builds up.

Your personal inflation rate

The CPI describes an average household. If more of your budget goes to rent, healthcare or college than the basket assumes, your own inflation can run higher. If you spend less on those, it can run lower. Look at your own largest categories when you plan.

What you can do about it

• Plan in real dollars. When setting a retirement or savings goal, ask what the amount will buy, not just its size. The retirement guide adjusts withdrawals for inflation.
• Keep only needed cash in low-interest accounts. Emergency money should be safe and easy to reach, and the rest can work harder.
• Look at the real rate before locking in. A fixed rate that is below inflation is a loss in buying power. Inflation-linked bonds exist for this reason.
• Ask for raises that keep up. If pay rises 2% in a year with 3% inflation, that is a pay cut in real terms.
• Remember debt. Inflation helps borrowers at a fixed rate, because the debt is repaid in cheaper dollars.

Common questions

Sources and further reading

• U.S. Bureau of Labor Statistics: Consumer Price Index home
• BLS: Consumer Price Index frequently asked questions
• Federal Reserve: Why does the Federal Reserve aim for inflation of 2 percent?
• Investor.gov: Inflation

This guide is for general education and is not financial advice. Historical inflation uses CPI-U annual averages (the same data as our Inflation Calculator). Past inflation does not predict the future, and the growth rates used in examples are illustrations.