1. What is the Retail Price Index (RPI)?

The Retail Price Index (RPI) is a measure of inflation that tracks the change in the cost of a fixed basket of retail goods and services over time. It compares current prices to prices in a base year to calculate the percentage change.

2. How Does the Calculator Work?

The calculator uses the RPI formula:

Where:

• \( Current CPI \) — Current Consumer Price Index value
• \( Base CPI \) — CPI value from the base period

Explanation: The formula calculates the percentage change in price levels between the current period and the base period.

3. Importance of RPI Calculation

Details: RPI is important for measuring inflation, adjusting wages and pensions, and as a reference for many commercial contracts. It helps economists and policymakers understand price trends in the economy.

4. Using the Calculator

Tips: Enter both current CPI and base CPI values (must be positive numbers). The result shows the percentage change in retail prices compared to the base period.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between RPI and CPI?
A: RPI includes housing costs like mortgage interest payments, while CPI doesn't. RPI tends to give higher inflation figures than CPI.

Q2: Why is a base period needed?
A: The base period provides a reference point (100) against which current prices are compared to calculate the percentage change.

Q3: How often is RPI calculated?
A: In most countries, RPI is calculated and published monthly by government statistical agencies.

Q4: What does a negative RPI mean?
A: A negative RPI indicates deflation - prices on average are lower than in the base period.

Q5: Where can I find CPI values?
A: CPI values are typically published by national statistical offices, central banks, or economic research organizations.