Inflation calculator
Enter an amount and two dates to see what it needs to be worth to keep up with US prices (from 1913), UK prices (from 1947) or the US money supply (from 1959). All three series run to Aug 2026.
With $100 or £100 from 2000
- $100 from January 2000 needs to be $198.45 in August 2026 to buy the same things in the US.
- To keep the same share of all US dollars it needs $500.27, 2.5 times the CPI figure.
- £100 from January 2000 needs to be £199.72 to match UK prices.
Work out what your money needs to be worth
Pick an amount, a measure and two months. Results update as you type.
How the amount needed grew, month by month
- US prices ($)
- UK prices (£)
- US money supply, M2 ($)
Source: US Bureau of Labor Statistics CPI-U, via FRED. Educational figures, not financial advice.
$100 or £100 from past years in today's money
Each row uses the average price level for that year, or the average M2 for that year, against Aug 2026. UK years before 1988 are on the long-run RPI.
| Year | US prices ($100) | UK prices (£100) | US money supply ($100) |
|---|---|---|---|
| 1913 | $3,389 | n/a | n/a |
| 1920 | $1,671 | n/a | n/a |
| 1930 | $2,006 | n/a | n/a |
| 1940 | $2,391 | n/a | n/a |
| 1950 | $1,392 | £3,667 | n/a |
| 1960 | $1,133 | £2,461 | $7,671 |
| 1970 | $863 | £1,654 | $3,881 |
| 1980 | $406 | £459 | $1,516 |
| 1990 | $256 | £257 | $724 |
| 2000 | $195 | £198 | $487 |
| 2005 | $172 | £184 | $357 |
| 2010 | $154 | £161 | $270 |
| 2015 | $141 | £144 | $193 |
| 2020 | $129 | £132 | $132 |
| 2024 | $107 | £107 | $110 |
“n/a” means the series does not reach back that far: UK prices start in 1947 and M2 in 1959. 2025 is left out because the US has no CPI figure for October 2025.
How the calculator works
Where the numbers come from, and where they fall short.
The formula
Amount × index at the end month ÷ index at the start month.
For US prices, $100 in January 2000 is multiplied by the CPI for the end month and divided by the CPI for January 2000. Buying power lost is one minus the start index divided by the end index. The yearly figure is the compound rate between the two months, shown only when they are at least 12 months apart.
Why UK figures before 1988 use RPI
The ONS CPI index starts in January 1988; the long-run RPI goes back to June 1947.
We join the ONS long-run retail prices index to the CPI at January 1988, scaling it so the two meet. RPI has usually risen faster than CPI because of the formula it uses to average prices and because it counts mortgage interest, so pre-1988 UK results are likely to be a little higher than a CPI-only calculation would give.
Why we show money printing (M2)
CPI follows the price of a weekly shop; M2 follows how many dollars exist.
Since 1959 M2 has grown much faster than consumer prices, and our Illusion of Wealth research found that a lot of the extra money showed up in the prices of assets rather than groceries. The M2 result answers a different question from CPI: how much you would need to hold the same share of all the dollars in circulation. The money supply page charts the series.
Missing and late months
The latest month can lag by one or two months; October 2025 has no US CPI.
CPI comes out two to six weeks after each month ends and M2 about four weeks after. If you pick an end month that is not out yet, the calculator uses the latest month available, up to three months back, and says so. The US government shutdown meant the BLS published no CPI for October 2025, so that month gives no US result rather than an estimate. Figures are educational and not financial advice; see our disclaimer.
Inflation calculator questions
Answers use the same data as the calculator.
How much is $100 from 2000 worth today?
Measured against US consumer prices, $100 in January 2000 has the buying power of $198.45 in August 2026, so the original $100 now buys about 50% of what it did. Measured against the money supply the gap is much wider: M2 grew enough that you would need $500.27 to hold the same share of all the dollars in circulation.
How much is £100 from 1970 worth today?
Using the average price level through 1970 (RPI-based, because the ONS CPI starts in 1988) against August 2026, £100 then is the same as about £1,654.13 now. Most of that rise came in the 1970s and early 1980s, when UK inflation reached 26.9% in August 1975. For comparison, $100 from 1970 needs to be about $862.79 in US prices.
What is the difference between inflation and money printing?
Inflation, as CPI measures it, is the rise in the price of a basket of everyday goods and services. Money printing here means growth in M2, the dollars held as cash, current accounts, savings deposits and money market funds. M2 has grown faster than prices over most long periods, and our research found much of the extra money went into assets such as shares, property and gold rather than into the weekly shop. That is why the calculator shows both: CPI tells you what it takes to keep buying the same things, M2 what it takes to keep the same share of all the money.
Which months and sources does the calculator use?
US prices use the BLS consumer price index for all urban consumers (CPI-U, not seasonally adjusted) from January 1913. UK prices use the ONS CPI index from January 1988 and the ONS long-run RPI before that, back to June 1947. Money printing uses the Federal Reserve's M2 series from January 1959. The data refreshes weekly. When the end month is not published yet, the calculator uses the latest month available and says so. The BLS published no CPI for October 2025, so that month returns no result rather than an estimate.
Important information
Capital at risk. The value of investments can fall as well as rise and you may get back less than you invest. Past performance is not a reliable indicator of future results. Educational information only, not financial advice. Read our disclaimer.