UK Inflation Calculator: What £100 in 1990 Is Worth Today (ONS CPI)
Adjust any pound amount between two years from 1949 to 2025 using ONS CPI annual averages (series D7BT). See what £100 in 1990 is worth in today's money.
See also: UK pounds inflation guide, cost of living by city, State Pension guide.
CPI-adjusted value
£1,384
£1,000 in 2015 → 2025
- Delta
- +£384
- Cumulative
- 38.4%
- Annualised
- 3.30%
- Direction
- forward, 10 years
How this is calculated
We apply the ratio of the ONS Consumer Prices Index (CPI, series D7BT) between the two years — the same method used by the Bank of England's public inflation calculator. For example £100 in 2015 scales by 133.9 / 100.0 = 1.339 to give £133.90 in 2024.
The annualised rate is the compound inflation per year required to turn the start value into the end value over the period. The cumulative figure is the total change over the whole span.
Source: ONS D7BT timeseries. Dataset uses ONS annual averages — for sub-year granularity consult the ONS website directly.
Popular inflation lookups
Common starting points — each a dedicated page with the CPI-adjusted value and context for that year.
This UK inflation calculator uses Office for National Statistics Consumer Prices Index data to adjust any pound amount between two years. From 1988 it uses ONS series D7BT (CPI all items, 2015 = 100); for 1949 to 1987 it uses ONS modelled historic CPI estimates, which ONS describes as indicative only. The CPI is the measure the Bank of England’s 2% inflation target is set on.
How to use this calculator
Forward (past → present): you start with an older pound amount and ask “what would that be worth today”. Typical use: translating an older salary, house price or family gift into today’s equivalent buying power.
Backward (present → past): you start with today’s amount and ask “what was this worth back then”. Typical use: historical wage comparisons or sanity-checking old salary or property statistics.
How to read the result
Adjusted amount is the CPI-equivalent of your input in the target year. Prices in 2025 were about 2.48 times their 1990 level on annual averages, so £1,000 in 1990 had the buying power of about £2,476 in 2025.
Cumulative change is the total percentage inflation over the whole period. From 2015 to 2025 the cumulative CPI rise is 38.4%, meaning goods that cost £100 in 2015 cost about £138 in 2025.
Annualised rate is the compound inflation rate per year you’d need to get from the start value to the end value over that span - for 1990 to 2025, 2.6% a year. Annual rates vary a great deal: the 12-month CPI rate peaked at 11.1% in October 2022 (ONS series D7G7).
Why CPI matters for UK tax
When tax thresholds are frozen while prices rise, the same real income is taxed more heavily over time (“fiscal drag”). In 2026/27:
- Income Tax thresholds: the Personal Allowance (£12,570), and the higher and additional rate thresholds, are frozen until April 2031.
- ISA allowance: £20,000 a year, unchanged since 2017/18.
- Personal Allowance taper: the £100,000 income level at which the Personal Allowance starts to be withdrawn has not changed since the taper was introduced in 2010/11. Adjusted by CPI, £100,000 in 2010 is about £154,810 in 2025 money.
CPI, CPIH and RPI
| Measure | What it covers | Status |
|---|---|---|
| CPI (D7BT) | Consumer prices, including rents but not owner occupiers’ housing costs or Council Tax | Basis of the Bank of England’s 2% target; used by this calculator |
| CPIH | CPI plus owner occupiers’ housing costs and Council Tax | ONS’s lead measure of inflation |
| RPI | Older index with a different method and coverage | ONS calls it a legacy measure, kept to meet existing users’ needs |
Source: ONS Consumer price inflation bulletin.
Worked examples
Translating a 1995 salary to 2025 money:
- 1995 salary: £25,000
- CPI 1995 annual average: 67.2
- CPI 2025 annual average: 138.4
- 2025 equivalent: £25,000 × (138.4 / 67.2) = £51,488
Nominal versus real investment growth (illustration, not a forecast):
- £10,000 invested in 1990, growing at an assumed 5% a year
- Nominal value in 2025: £55,160
- Real value in 1990 pounds: £55,160 ÷ 2.48 = £22,279
- Real growth: about 2.3% a year
This is why financial planning needs to distinguish nominal returns from real returns.
Data sources and cadence
- CPI index: ONS D7BT, annual averages, 1988 to 2025.
- Earlier years: ONS consumer price inflation, historical data, UK 1950 to 1988, modelled estimates rebased onto the 2015 = 100 scale. ONS says these are not National Statistics and are for indicative purposes.
- Update frequency: once a year (January), after ONS has published all twelve months of the previous year. No forecast years are included.
- Annual average vs a single month: we use the annual average. The headline “inflation rate” in the news is the 12-month rate for the latest month, which is a different number.
Our methodology page lists the site’s data sources.
Limitations
- Average not personal: CPI is based on a basket representing typical household spending. Your own inflation depends on what you spend money on.
- Quality adjustments: ONS adjusts prices for changes in quality, so a price index is not the same as the change in the sticker price of a particular item.
- Owner-occupied housing: CPI excludes owner occupiers’ housing costs. If housing is a large part of your costs, CPIH may be more representative.
- Investment + savings: this calculator translates PURCHASING POWER, not investment returns.
Related calculators and guides
- Cost of living by city - regional variation in rent, council tax and median pay
- Salary calculator - translate gross salary into take-home
- UK salary statistics - where common salaries rank against national percentiles
- UK pounds inflation calculator guide - detailed explainer including fiscal drag mechanics
- State Pension guide - how the State Pension is uprated
- How tax works - thresholds frozen vs CPI uprating
- Tax deadlines 2026/27 - all annual UK tax dates
Worked examples
Related calculators
Other UK tax calculators that pair with the Inflation.
Frequently asked questions
What is £100 from 1990 worth today in the UK?
Using ONS CPI annual averages (series D7BT), £100 in 1990 had the same buying power as about £248 in 2025, the latest full year published. Use the calculator above for any other pair of years.
Where does the CPI data come from?
From 1988 onwards, ONS series D7BT, the Consumer Prices Index (all items, 2015 = 100), as annual averages. For 1949 to 1987, ONS modelled historic CPI estimates, chained onto the same scale. ONS describes those earlier estimates as indicative rather than measured, so treat results before 1988 as approximate.
What is the difference between CPI and RPI?
Both measure changes in consumer prices but with different methods and coverage. The CPI is the measure the Bank of England inflation target is set on. ONS describes CPIH (CPI including owner occupiers' housing costs) as its lead measure of inflation and the RPI as a legacy measure kept to meet existing users' needs. This calculator uses CPI.
Is this the same as the Bank of England inflation calculator?
Not necessarily. Inflation calculators can give different answers for the same years because they use different index series, different series for early years, and different reference points (an annual average versus a single month). This calculator uses ONS CPI annual averages throughout.
Why can I only pick certain years?
Every calendar year from 1949 to 2025 is available. The series stops at the last full year ONS has published, because an annual average needs all twelve months, and it does not include forecasts.
Does this account for regional differences?
No. The CPI is a single UK-wide index, so this calculator cannot show how prices changed in one region compared with another. ONS publishes separate analysis of how price levels differ between regions, which is a different question from inflation over time.