Inflation in the UK
UK inflation is measured by the Office for National Statistics (ONS) using the Consumer Prices Index (CPI). The Bank of England targets 2% inflation and moves the base rate to steer towards it. When inflation runs above target, cash held in low-interest accounts loses real value, which this calculator makes concrete.
- Measured by: ONS Consumer Prices Index (CPI).
- BoE target: 2% per year.
- Shelter: tax-free growth inside an ISA helps your money keep pace.
UK-specific questions
Which inflation measure does the UK use?
The headline measure is CPI, published monthly by the ONS. You may also see CPIH, which additionally includes owner-occupier housing costs.
How can I protect savings from UK inflation?
Aim for a return above inflation and use tax-free wrappers like an ISA so more of that return is kept. Cash left in a low-rate account typically loses purchasing power when inflation is above the interest earned.
Understanding Inflation and Purchasing Power
Inflation is the gradual rise in the general price level, which means each unit of currency buys a little less over time. It is the quiet tax on savings: money left in a low-interest account can lose real value every year even as its nominal balance stays the same. This guide explains how to measure that erosion and how to protect against it.
Nominal vs. Real Value
The future purchasing power of an amount is Real = Nominal ÷ (1 + inflation)ⁿ. At 4% annual inflation, $10,000 today has the buying power of only about $6,760 in ten years and roughly $4,560 in twenty. Nothing changed in your account balance - but what it can purchase shrank by nearly half. Understanding this difference is the foundation of sound long-term planning.
The Rule of 70
A quick way to gauge inflation's bite is the Rule of 70: divide 70 by the inflation rate to estimate the years it takes for prices to double. At 3.5% inflation, prices double in about 20 years; at 7%, in just 10. The same rule, applied to your investment return, tells you how fast your money doubles - so the gap between the two rates is what really grows your wealth.
How to Protect Your Money
Beating inflation means earning a return above the inflation rate. Historically, diversified equities, inflation-linked government bonds, and real assets have outpaced inflation over long periods, while cash typically lags it. The goal is a positive real return - your nominal return minus inflation - so your savings grow in buying power, not just in number.
Frequently Asked Questions
Why does my savings account lose value if the balance never drops?
Because prices rise faster than the interest you earn. If your account pays 1% but inflation is 4%, your money loses about 3% of its purchasing power each year even though the number on your statement is unchanged.
What is a 'real' return?
The real return is your nominal return minus the inflation rate. A 6% investment return during 4% inflation is only a ~2% real return - that 2% is the genuine growth in what your money can buy.
Is some inflation actually normal?
Yes. Most central banks target around 2% inflation as a sign of a healthy, growing economy. Problems arise when inflation runs well above target for a sustained period, rapidly eroding cash savings and fixed incomes.
How can I estimate future costs like education or retirement?
Project today's cost forward at an assumed inflation rate using the compound formula. Big-ticket categories like education and healthcare often inflate faster than the headline rate, so model them separately with a higher assumption.