£1 in 1920 is equivalent in purchasing power to about £0.91 in 1921.
The pound had an average **deflation** rate of -8.70% per year since 1920, producing a cumulative price change of -8.70%.
Purchasing power *increased* by 8.70% in 1921 compared to 1920. On average, you would have to spend 8.70% *less* money in 1921 than in 1920 for the same item.
This is an example of **deflation**.

This means that prices in 1921 are 8.7% lower than average prices since 1920, according to the Office for National Statistics composite price index.

The 1920 inflation rate was 15.53%. The inflation rate in 1921 was -8.70%. The 1921 inflation rate is lower compared to the average inflation rate of 3.99% per year between 1921 and 2021.

Inflation rate is calculated by change in the composite price index (CPI). The CPI in 1921 was 23.10. It was 25.30 in the previous year, 1920. The difference in CPI between the years is used by the Office for National Statistics to officially determine inflation. Because the 1921 CPI is less than 1920 CPI, negative inflation (also known as deflation) has occurred.

⌃

Average inflation rate | -8.70% |

Converted amount (£1 base) | £0.91 |

Price difference (£1 base) | £-0.09 |

CPI in 1920 | 25.300 |

CPI in 1921 | 23.100 |

Inflation in 1920 | 15.53% |

Inflation in 1921 | -8.70% |

£1 in 1920 | £0.91 in 1921 |

Our calculations use the following inflation rate formula to calculate the change in value between 1920 and 1921:

CPI in 1921
CPI in 1920

×

1920 GBP value

=

1921 GBP value

Then plug in historical CPI values. The U.K. CPI was 25.3 in the year 1920 and 23.1 in 1921:

23.125.3

×

£1

=

£1 in 1920 has the same "purchasing power" or "buying power" as £0.91 in 1921.

To get the total inflation rate for the 1 years between 1920 and 1921, we use the following formula:

CPI in 1921 - CPI in 1920CPI in 1920

×

100

=

Plugging in the values to this equation, we get:

23.1 - 25.325.3

×

100

=

Politics and news often influence economic performance. Here's what was happening at the time:

- The League of Nations' first assembly takes place in Paris.
- The British Parliament passes the Fourth Home Rule Act, dividing Ireland into two parts and leading to a yearlong Anglo-Irish war in the southern counties.
- The Catholic Church canonizes Joan of Arc, formally making her a saint.
- The 19th Amendment to the constitution is ratified, granting U.S. woman suffrage for the first time.

Raw data for these calculations comes from the composite price index published by the UK Office for National Statistics (ONS). A composite index is created by combining price data from several different published sources, both official and unofficial. The Consumer Price Index, normally used to compute inflation, has only been tracked since 1988. All inflation calculations after 1988 use the Office for National Statistics' Consumer Price Index, except for 2017, which is based on The Bank of England's forecast.

You may use the following MLA citation for this page: “Inflation Rate in 1921 | UK Inflation Calculator.” Official Inflation Data, Alioth Finance, 14 Sep. 2021, https://www.officialdata.org/UK-inflation-rate-in-1921.

Special thanks to QuickChart for their chart image API, which is used for chart downloads.

in2013dollars.com is a reference website maintained by the Official Data Foundation.

Average inflation rate | -8.70% |

Converted amount (£1 base) | £0.91 |

Price difference (£1 base) | £-0.09 |

CPI in 1920 | 25.300 |

CPI in 1921 | 23.100 |

Inflation in 1920 | 15.53% |

Inflation in 1921 | -8.70% |

£1 in 1920 | £0.91 in 1921 |