Inflation Calculator
See what money was worth in the past or what it will be worth in the future with UK inflation rates.
By Konstantin Iakovlev · Founder, Calks.uk
Last updated: · Verified against HMRC and GOV.UK 2026/27 rates
£100.00 in 2000 is equivalent to
£236.32
in 2025 (25 years, 3.5% avg inflation)
Purchasing Power Change
57.7% lost
Cumulative Inflation
136.3%
Price Multiplier
2.36x
Disclaimer
This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.
How It Works
The Consumer Prices Index (CPI) tracks the average price change of a weighted basket of around 700 goods and services purchased by UK households. The Office for National Statistics collects approximately 180,000 price quotes each month from shops, online retailers, and service providers across the country. Each item's weight reflects its share of total household spending, updated annually from the Living Costs and Food Survey.
To convert a historical amount to today's prices, the calculator divides the current CPI index value by the historical index value, then multiplies by the original sum. For example, the CPI index stood at 68.0 in January 2000 and approximately 136.0 in early 2026, giving a ratio of 2.0. This means £100 in January 2000 had roughly the same purchasing power as £200 in 2026.
CPI differs from the older Retail Prices Index (RPI) in several ways: CPI excludes mortgage interest payments and council tax, uses a geometric rather than arithmetic mean for averaging prices, and covers a broader population including foreign visitors' spending. CPIH extends CPI by adding owner-occupiers' housing costs. The calculator defaults to CPI as it is the UK government's preferred inflation measure and the Bank of England's target index.
How UK inflation is measured. Office for National Statistics tracks ~700,000 prices monthly from ~20,000 outlets. The Consumer Prices Index (CPI) is the main measure since 2003 — excludes housing costs (mortgage interest, council tax). CPIH includes owner-occupier housing costs (preferred by ONS since 2017). RPI is the older measure, still used for index-linked gilts and some pensions — typically 0.5-1% higher than CPI. Both released around the 15th of each month.
What's a 'normal' UK inflation rate? Bank of England target is 2% CPI. Historical UK averages: 1990s ~3%, 2000s ~2.5%, 2010s ~1.8%, 2020-2024 spike to 11% (COVID supply chains + Ukraine energy crisis), 2026 around 2-3%. Periods of 5%+ inflation halve purchasing power within 14 years (Rule of 72). Cash savings need rates above inflation to maintain value. Pensions with triple lock (highest of earnings, CPI, 2.5%) preserve retiree purchasing power.
How inflation affects financial decisions. Real return = Nominal return − Inflation. 4% savings rate with 3% inflation = 1% real return. 7% investment return with 3% inflation = 4% real return. Long-term planning (pensions, retirement income, mortgages) should always use REAL figures. Cash sitting in low-interest accounts during 5%+ inflation loses 4-5% purchasing power annually. Invest in real assets (property, equities, index-linked bonds) when inflation is above your savings rate.
Inflation across asset classes. Cash savings: lose value above inflation rate. Equities: UK FTSE All-Share has averaged 7% real return since 1900 — beats inflation comfortably long-term. Property: 3-5% real return historically, with high regional variation. Gold: zero real return long-term but hedges against currency debasement and crisis. Index-linked gilts: explicitly designed to track inflation. Crypto: too short history for reliable inflation hedge claim.
Adjusting a 2010 salary to 2026 equivalent
- Original salary in 2010: £32,000
- CPI index January 2010: 112.4, CPI index January 2026: approximately 139.7
- Inflation multiplier: 139.7 / 112.4 = 1.243
- Equivalent 2026 salary: £32,000 x 1.243 = £39,776
- Cumulative inflation over the period: 24.3%, meaning prices rose by nearly a quarter
Frequently Asked Questions
- What is UK inflation 2026?
- Consumer Price Index (CPI) target is 2% set by Bank of England. 2024 average 3.2%; 2025 forecast 2.5%; 2026 expected 2.0-2.5%. Peak: 11.1% October 2022 (highest in 41 years). RPI (Retail Price Index): typically 1% higher than CPI. CPIH (CPI including owner housing costs): closer to true household experience. Bank of England base rate set to control inflation — was 5.25% peak 2023, currently 4.75% 2026.
- How does inflation erode purchasing power?
- 3% inflation HALVES purchasing power in 24 years. 5% inflation halves in 14 years. 10% inflation halves in 7 years. £100,000 saved in 2000 at 3% annual inflation: 2024 purchasing power = £49,000. £100,000 in 1980: 2024 value = £21,000 (40+ years cumulative). Pension implication: £30k/year retirement income today needs ~£55k in 20 years at 3% inflation to maintain lifestyle.
- Real vs nominal returns.
- Real return = nominal return − inflation. £100k savings at 4.5% in 3% inflation environment = 1.5% real return. Cash savings often lose purchasing power in real terms. Long-term real returns: equities 4-6%; bonds 0-2%; cash −1 to +1%; property 2-3%. Inflation-linked Gilts: principal + interest adjusted by RPI/CPI — but currently negative real yields (you pay for inflation protection).
- How to protect against inflation.
- Equities: long-term outpace inflation 4-6% real returns. ISA wrapper: tax-free growth = effectively higher real return. Inflation-linked Gilts and NS&I Index-Linked (closed to new investors): direct protection. Property: rental income tends to rise with inflation. Pension: annuities WITHOUT inflation protection lose 30-50% real value over 20-year retirement. Always quote pension projections in REAL terms (after inflation) not nominal.