$100 in 1918 has the buying power of $2,231.39 in September 2026. Prices are 2,131.4% higher, an average of 2.91% a year, by the official Consumer Price Index (CPI-U): 1918's average index was 15.1 and September 2026's is 336.940. Put the other way, $100 in September 2026 buys what $4.48 did in 1918.
Inflation in 1918 was 18.0% (the change in the year's average CPI from 1917; December to December, 20.4%), the highest of any year since 1914.
| Year | Average CPI-U | Inflation | $100 then is worth today |
|---|---|---|---|
| 1913 | 9.9 | — | $3,403.43 |
| 1914 | 10.0 | +1.0% | $3,369.40 |
| 1915 | 10.1 | +1.0% | $3,336.04 |
| 1916 | 10.9 | +7.9% | $3,091.19 |
| 1917 | 12.8 | +17.4% | $2,632.34 |
| 1918 | 15.1 | +18.0% | $2,231.39 |
| 1919 | 17.3 | +14.6% | $1,947.63 |
| 1920 | 20.0 | +15.6% | $1,684.70 |
| 1921 | 17.9 | −10.5% | $1,882.35 |
| 1922 | 16.8 | −6.1% | $2,005.60 |
| 1923 | 17.1 | +1.8% | $1,970.41 |
2.91% a year, compounded from the middle of 1918 to September 2026: prices are 2,131.4% higher in all, so a dollar from 1918 is worth $22.31 today.
The Bureau of Labor Statistics' Consumer Price Index for All Urban Consumers (CPI-U), all items, U.S. city average, not seasonally adjusted, which runs back to January 1913. A year's figure is the average of its monthly indexes, as BLS computes annual averages; today's figure is the latest month, September 2026, so the answer moves each month when BLS publishes a new CPI.
1917 · Inflation calculator, any month since 1913 · 1919
Source: BLS CPI-U, all items, U.S. city average, not seasonally adjusted (FRED CPIAUCNS); through 2006, BLS's official annual averages. The answer moves each month, when BLS publishes a new CPI.