CPI vs RPI inflation: what is the difference between ONS measures?

The Office for National Statistics calculates CPI, RPI and CPIH each month. What are they and what do they reveal about UK inflation?

Person holding a basket of supermarket goods
CPI is the official measure of UK inflation, while RPI is more historical
(Image credit: coldsnowstorm via Getty Images)

Inflation, as measured by the Consumer Prices Index (CPI), slowed to 3% in January, its lowest level since March 2025.

Inflation has remained above the Bank of England’s 2% target since October 2024, but is finally projected to fall back to 2% in the second quarter of 2026.

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Sam Walker
Writer

Sam has a background in personal finance writing, having spent more than three years working on the money desk at The Sun.

He has a particular interest and experience covering the housing market, savings and policy.

Sam believes in making personal finance subjects accessible to all, so people can make better decisions with their money.

He studied Hispanic Studies at the University of Nottingham, graduating in 2015.

Outside of work, Sam enjoys reading, cooking, travelling and taking part in the occasional park run!

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