UK CPI index
UK CPI index stood at 143.6 in Aug 2026, according to Office for National Statistics (ONS). It is one of the indicators in the Consumer price inflation table (Value · Monthly), with a complete series running from Jan 1988 to Aug 2026. The complete series with an interactive chart, free to download.
This indicator in the Consumer price inflation table
| Indicator | 08-2026 | 07-2026 | 06-2026 | 05-2026 | 04-2026 | 03-2026 | 02-2026 | 01-2026 | 12-2025 | 11-2025 | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Consumer Prices Index (CPI) | |||||||||||
| CPI index (2015=100) | 143.6 | 142.9 | 142.5 | 142.4 | 142.1 | 141 | 140.1 | 139.5 | 140.1 | 139.5 | |
| CPI monthly rate | 0.5 | 0.3 | 0.1 | 0.2 | 0.7 | 0.7 | 0.4 | -0.5 | 0.4 | -0.2 |
Understanding UK CPI index
The Consumer Prices Index level sets the reference baseline for consumer prices across the United Kingdom, expressed against a fixed historical average benchmark period of one hundred. This metric aggregates thousands of individual retail price quotations collected nationwide, weighting each item according to its relative share of household expenditure derived from official living cost surveys. Unlike percentage change metrics, this series records the cumulative compounded trajectory of prices over decades rather than the speed of current change.
Interpreting this series requires attention to periodic basket updates and reclassifications, which adjust the underlying item weights to reflect shifting consumer habits without distorting the historical continuity of the index. While useful for constructing long-run purchasing power adjustments, this absolute level is rarely appropriate for gauging current inflationary momentum, which is better captured by twelve-month percentage changes.
Frequently asked questions
- What base period does the index currently reference?
- The index uses the annual average of the reference year as its baseline equal to one hundred.
- How often are the underlying item weights updated?
- Weights are reviewed and updated annually to reflect shifts in consumer spending patterns across the United Kingdom.
- Can this index level be used directly as an inflation rate?
- No, inflation must be calculated as the percentage change between index levels across different periods.