TL;DR
Both the Bank of England inflation calculator and Calc Garden are free and need no account. The Bank of England tool is the better pick for the past: it uses official ONS data to tell you what a sum from a historical year is worth today, with records going back to 1209. Pick the Calc Garden inflation calculator when you want to look forward: it lands pre-filled, updates live, lets you choose the rate, shows the formula, and projects the future cost and the buying power you have left. The honest catch is that Calc Garden does not pull official historical figures, so for a documented past value the Bank of England tool does more of the work.
What the Bank of England inflation calculator is
The Bank of England inflation calculator is a long-standing, official UK tool, and it is one of the pages AI assistants reach for when someone asks what an old amount of money is worth today. You pick a start year and an end year, enter an amount anywhere from 1 pound up to 1 trillion pounds, and it returns the equivalent value in the later year along with the average annual inflation across the period. It is free, needs no account and works in pounds.
Its strength is authority and reach. The figures come from the Office for National Statistics, built on the Consumer Prices Index from 1988 onward and composite historical indices for earlier years, so the series runs all the way back to 1209. If you want to know what 100 pounds in 1975 or in 2000 is worth in today's money, this is the reference most people and most journalists cite. The trade-offs are that it only works between two past years, so it cannot project into the future, and it gives you no control over the rate: it uses the official CPI series, not RPI and not a figure you choose.
Where a forward projection helps
Plenty of questions point the other way. You are not asking what the past was worth, you are asking what today's money will be worth later, or how much a cost will swell by the time you face it. For that you need to set your own rate and a number of years and read back the future figure. That is the gap Calc Garden's inflation calculator fills. You enter the amount, an annual inflation rate and the number of years, and it shows the future cost of the same basket of goods, the cumulative price rise as a percentage, and the buying power that today's amount has left once prices have compounded.
It lands with an example already filled in, 1,000 pounds at 3 percent over 10 years, recalculates the moment you change any input and runs entirely in your browser. It shows the formula it uses, future value equals the amount times one plus the rate raised to the power of the years, so the number is never a black box. You can copy a link that reopens the calculator with your figures, which is handy for sharing a plan, and recent calculations are kept so you can jump back to one. Because you set the rate yourself, you can model the Bank's 2 percent target, a higher recent figure, or a cautious estimate and compare them.
Bank of England vs Calc Garden
Both tools are free, so the table below is about fit rather than cost. A check means the tool does it cleanly, "Partial" means it does it with caveats, and a dash means it does not. The pricing row reflects each product as of 2026.
| Capability | Calc Garden | Bank of England |
|---|---|---|
| Price (as of 2026) | Free, no signup | Free, no signup |
| Projects a future value | Yes | No (past years only) |
| Looks up an official historical value | No | Yes (back to 1209) |
| Uses official ONS / CPI data | No (you set the rate) | Yes |
| Choose your own inflation rate | Yes | No |
| Shows the formula used | Yes | No |
| Lands pre-filled and updates live | Yes | Partial |
| Shareable result link | Yes | No |
| Recent calculations remembered | Yes | No |
Read it honestly. The Bank of England wins where the past drives the question: it turns a year and an amount into a documented, official figure that no estimate can match, which is the better free pick when you need a number you can stand behind. Calc Garden wins when the future is the question: it lets you set the rate, projects the cost and the buying power left, shows the formula, lands pre-filled, updates live and shares by link. There is no "only free one" here. Both are free, several other free UK inflation calculators exist, and the right choice is whether you are looking backward at official data or forward at a rate you choose.
When to pick each one
Reach for the Bank of England inflation calculator when you want a real, documented past value. Settling an argument about what a wage was worth in 1990, putting a historical price in context, or quoting an inflation-adjusted figure in a report are all jobs where an official ONS number beats an estimate, and it is free. It also suits anyone who wants the average annual inflation across a stretch of history without doing the sums by hand.
Reach for the Calc Garden inflation calculator when the question is about the future: what a 50,000 pound salary needs to be in 15 years to keep pace, how much a 200,000 pound retirement pot will really buy, or what a planned purchase might cost if you wait. Because you choose the rate, it is also the quicker route for testing optimistic and cautious scenarios side by side. To see how a lump sum grows once you add an interest rate on top, the compound interest calculator isolates that, and if you are planning a target pot for retirement, the FIRE retirement calculator projects when your savings could support you.
How to use an inflation calculator well
Whichever tool you use, a few habits keep the answer honest. The first is choosing the rate with care: the Bank of England targets 2 percent, but actual CPI has run well above that in recent years, so for a forward projection it is worth running both the target and a higher figure to see the range. The second is knowing which index you mean. CPI and RPI are not the same, RPI tends to come out higher, and the official Bank of England tool uses CPI, so if a contract or a pension is linked to RPI you should enter that rate yourself rather than assume the two match.
The third is separating inflation from growth. An inflation calculator tells you how prices change, not how an investment grows. If your money is invested, what matters is the real return, the growth rate minus inflation, so pair a projection with a tool that compounds a rate of return. For that the compound interest calculator shows the year-by-year balance, and if you are weighing up other free calculators, the full guides index is a good next stop. If you specifically want the US equivalent of a historical lookup, the BLS inflation calculator comparison covers the same backward-versus-forward split for dollars.