What $100,000 Will Be Worth: The Inflation Erosion Table
At 3% inflation, the $100,000 you hold today buys only about $74,000 of goods in 10 years and $41,000 in 30. Inflation is a silent tax on cash — and the reason savings have to grow just to stand still.
We computed the future purchasing power of $100,000 across common time horizons and inflation rates.
Purchasing power of $100,000 over time
Each cell is what $100,000 will actually buy, in today's dollars, after that many years at that inflation rate.
| Years | 2% inflation | 3% inflation | 4% inflation |
|---|---|---|---|
| 5 years | $90,573 | $86,261 | $82,193 |
| 10 years | $82,035 | $74,409 | $67,556 |
| 15 years | $74,301 | $64,186 | $55,526 |
| 20 years | $67,297 | $55,368 | $45,639 |
| 25 years | $60,953 | $47,761 | $37,512 |
| 30 years | $55,207 | $41,199 | $30,832 |
What it means
Cash doesn't hold its value — at the long-run U.S. average near 3%, money loses roughly half its purchasing power in about 24 years. That's why money you won't need for years generally has to be invested to earn more than inflation; what matters is your real (after-inflation) return. See how inflation eats into returns with the savings, taxes & inflation calculator.
How we calculated this
Purchasing power = $100,000 ÷ (1 + inflation)^years. The figures scale linearly, so $50,000 is exactly half of each, and $1,000,000 is ten times. We used constant annual inflation; real-world inflation varies year to year.
How much will $100,000 be worth in 20 years?
About $67,000 in today's purchasing power at 2% inflation, $55,000 at 3%, and $46,000 at 4%. The cash amount stays $100,000 — it simply buys less.
What inflation rate should I assume?
The long-run U.S. average is roughly 3% a year, though it swings widely. Using 3% is a reasonable planning baseline; use a higher rate to be conservative.
How do I protect my money from inflation?
Hold money you won't need soon in investments expected to outpace inflation. What counts is your real return — your investment return minus inflation — not the headline rate.
How long until inflation halves my money?
At 3% inflation, purchasing power falls by about half in roughly 24 years (the rule of 72: 72 ÷ 3). At 4% it's about 18 years.