Inflation

Inflation is the rate at which the general level of prices rises over time, which means each dollar buys a little less than it did the year before. In the US it is measured by the Bureau of Labor Statistics through the Consumer Price Index, a basket of goods and services covering housing, food, energy, medical care, and transport. When the news says inflation ran at 3%, it means that basket costs 3% more than it did twelve months earlier. The Federal Reserve targets 2% a year, on the theory that a small and predictable rise keeps the economy moving without eroding anyone's savings too quickly.

Inflation is not the same as any single price going up. It is the average across the whole basket, which is why your personal inflation can run hotter than the headline: if rent and groceries dominate your spending while televisions get cheaper, the official figure will flatter you. Roughly 3% a year is the century-long US average, with spikes such as the 9.1% peak in June 2022 in between. At 3%, prices double roughly every 24 years.

The Bureau of Labor Statistics prices the same basket of goods and services every month and publishes the change as the CPI. Housing carries the largest weight in that basket, followed by food and energy, which is why a rent renewal can move your personal inflation more than a fuel price move moves the headline. The Fed then uses the figure to decide whether to lean on interest rates, because rates are the tool it has for cooling demand when prices run hot.

For your money, inflation works like compounding in reverse. A balance of $50,000 left flat for ten years at 3% inflation has the same purchasing power as $37,200 does today, because prices rose 34% while the balance did nothing. The arithmetic mirrors the compound interest formula: instead of multiplying your balance by 1.03 each year, you divide its real value by 1.03. The same logic prices the raise: a salary that gains 3% while prices gain 3% is standing still, and a salary that gains 2% is going backwards. This is why the real return matters more than the number on the statement, and why the inflation-adjusted return calculator exists at all.

Inflation touches every dollar an American holds: the paycheck, the HYSA, the 401(k), and the mattress stash. Social Security recipients get an annual COLA adjustment tied to the CPI-W (2.8% for 2026), and Treasury I Bonds pay a rate that adjusts with inflation twice a year. Most salaries get nothing automatic, which is why a raise that matches inflation keeps you level rather than ahead. Cash is the asset that pays the inflation tax in full every year, because a checking account at 0.01% is a rounding error against a 3% basket.

I have a colleague named Brent (yes, that Brent) who kept $80,000 in his checking account for three years because the app was convenient. At 3% inflation, that convenience cost him roughly $6,800 of purchasing power, plus the roughly $10,800 in interest a 4.5% HYSA would have paid. He bought nothing with the money and still paid for it.

The highest-leverage thing most Americans can do is keep exactly one month of expenses in checking, park the rest in a high-yield account or inflation-indexed bonds, and measure every return in real terms. Run your own numbers through the inflation calculator or the purchasing power calculator before assuming your cash is standing still.