Close this search box.

Table of Contents

Retail Price Index (RPI)


The Retail Price Index (RPI) is a measure of inflation that is commonly used in the United Kingdom. It calculates the average change in the price of goods and services purchased by most households over time. This index includes items such as housing costs and mortgage interest payments which are not included in the Consumer Price Index (CPI).


Retail Price Index (RPI): /ˈriːteɪl praɪs ˈɪndeks/

Key Takeaways

<ol><li>RPI, or Retail Price Index, is a measure of inflation in the UK, calculated by tracking the price changes of a specific set of goods and services overtime.</li><li>Unlike the Consumer Price Index (CPI), RPI includes housing costs such as mortgage interest payments and council tax, therefore providing a more comprehensive view of the average cost living for households.</li><li>Though RPI is widely used, it has been criticized for overstating inflation and is no longer considered a “national statistic” by the UK Office for National Statistics. However, it still remains in use for calculating cost of living adjustments in certain contexts, including wage growth and pensions.</li></ol>


The Retail Price Index (RPI) is a crucial measure in the business/finance world as it represents the inflation rate and the cost of living from a consumer’s perspective. It measures the average change in the prices of goods and services bought for the purpose of consumption by the majority of households. This metric is essential for both businesses and consumers alike. Businesses use it to determine price adjustments for their products or services, calculate real income, or in wage negotiations, while individuals can use it to understand changes in the economy’s general price level. Therefore, RPI plays a pivotal role in financial planning, policy making, and economic analysis.


The Retail Price Index (RPI) is a critical tool used in finance/business to measure the rate of inflation, which is integral in understanding the economic health of a certain country or region. Functioning as a measurement index for changes over time in the general level of retail prices, the RPI is essentially used to demonstrate how the purchasing power of money changes over time due to inflation. For instance, a rise in RPI indicates a decrease in purchasing power as prices of goods and services are climbing. The ability to gauge the rate of inflation allows businesses and individuals to make informed decisions about spending, saving, and investing.Beyond this, the RPI also affects several other vital aspects of the economy. For starters, it is often employed in wage negotiations as it helps to determine how much wages should rise to keep up with inflation. Similarly, it is employed to adjust state benefits, pensions, and tax allowances for the impact of inflation, known as “indexation”. RPI can also be used to adjust lease amounts, as many leases contain clauses allowing regular rent increases based on the current inflation rate. Essentially, it provides a crucial reference point for many economic activities, enhancing financial planning, policy formulation and decision-making across numerous sectors.


1. Utility Bills: Energy providers often adjust their prices according to the Retail Price Index. If the RPI increases, the providers might raise their prices to cover their increasing costs. For example, in the UK, British Gas might increase its tariffs annually in line with the RPI, affecting homeowners and businesses with fluctuating utility bills. 2. Public Transportation: In the UK, train fares are usually adjusted annually in relation to the RPI. An increase in the RPI often leads to a surge in train ticket prices. For instance, in 2019, due to a 2.8% rise in the RPI, UK commuters saw the biggest train fare increase in 5 years. 3. Pension Payouts: Some pensions, such as the UK’s state pensions, are linked to the RPI. This means the value of the pension increases each year in line with the Retail Price Index to safeguard against inflation. This protects the pensioners, as the buying power of their monthly payments remains consistent with the cost of living.

Frequently Asked Questions(FAQ)

What is the Retail Price Index (RPI)?

The Retail Price Index (RPI) is a measure of inflation that is calculated by taking into account the prices of a defined set of goods and services, including mortgage interest payments and council tax. This index is an older measurement of inflation that is still used for certain purposes, such as adjusting pensions or rail fares.

How is RPI calculated?

The RPI is calculated by following a specific list of goods and services over time and watching for changes in their prices. The list represents a ‘typical’ basket of goods and services, and it is intended to reflect the spending habits of the majority of people.

How is RPI different from the Consumer Price Index (CPI)?

The primary difference between the Retail Price Index and the Consumer Price Index is the basket of goods and services they measure. RPI additionally takes into account housing costs like mortgage interest payments and council tax, whereas CPI does not.

Why is RPI important in business and finance?

RPI is important because it can provide a measure for inflation. Many contracts, pensions, and regulated price adjustments are linked to RPI, so it has real-world impacts on the costs businesses face and the prices consumers pay.

Is RPI used worldwide?

RPI is a specific measure used in the UK. Other countries use similar indices, but they might be called different names, such as the CPI in the United States. However, the methodology may be different.

Can RPI be negative?

Yes, if average prices fall over a period of time, then RPI can be negative. This situation is known as deflation.

How often is the RPI updated?

The RPI is usually updated on a monthly basis. It’s calculated by the Office for National Statistics in the UK.

What are some criticisms of RPI?

Some economists argue that RPI tends to overstate inflation because of its calculation formula. As a result of this and other issues, since 2013, RPI is no longer considered an official national statistic in the UK, but it is still used for adjusting certain prices and expenditures.

Related Finance Terms

Sources for More Information

About Our Editorial Process

At Due, we are dedicated to providing simple money and retirement advice that can make a big impact in your life. Our team closely follows market shifts and deeply understands how to build REAL wealth. All of our articles undergo thorough editing and review by financial experts, ensuring you get reliable and credible money advice.

We partner with leading publications, such as Nasdaq, The Globe and Mail, Entrepreneur, and more, to provide insights on retirement, current markets, and more.

We also host a financial glossary of over 7000 money/investing terms to help you learn more about how to take control of your finances.

View our editorial process

About Our Journalists

Our journalists are not just trusted, certified financial advisers. They are experienced and leading influencers in the financial realm, trusted by millions to provide advice about money. We handpick the best of the best, so you get advice from real experts. Our goal is to educate and inform, NOT to be a ‘stock-picker’ or ‘market-caller.’ 

Why listen to what we have to say?

While Due does not know how to predict the market in the short-term, our team of experts DOES know how you can make smart financial decisions to plan for retirement in the long-term.

View our expert review board

About Due

Due makes it easier to retire on your terms. We give you a realistic view on exactly where you’re at financially so when you retire you know how much money you’ll get each month. Get started today.

Due Fact-Checking Standards and Processes

To ensure we’re putting out the highest content standards, we sought out the help of certified financial experts and accredited individuals to verify our advice. We also rely on them for the most up to date information and data to make sure our in-depth research has the facts right, for today… Not yesterday. Our financial expert review board allows our readers to not only trust the information they are reading but to act on it as well. Most of our authors are CFP (Certified Financial Planners) or CRPC (Chartered Retirement Planning Counselor) certified and all have college degrees. Learn more about annuities, retirement advice and take the correct steps towards financial freedom and knowing exactly where you stand today. Learn everything about our top-notch financial expert reviews below… Learn More