Data Sources and Verification — Inflation Time Machine

Version 1.0
Last updated: February 2026

Transparent arithmetic includes transparent data.

This page documents the CPI datasets used by the Inflation Time Machine and their source provenance.

Data Structure

The calculator uses annual Consumer Price Index (CPI) index values for each supported country.

Each country dataset consists of:

• Year
• Annual CPI index value

No smoothing, rebasing, interpolation, or normalization is performed within the calculator. All calculations use the raw index values as stored in the dataset.

Supported Countries and Sources

CPI datasets are loaded from static country-specific data files.

• Canada
  Source: Statistics Canada
  Coverage: 1914–2025
• United States
  Source: U.S. Bureau of Labor Statistics (BLS)
  Coverage: 1913–2024
• Australia
  Source: Australian Bureau of Statistics (ABS)
  Coverage: 1949–2022
• United Kingdom
  Source: Office for National Statistics (ONS)
  Coverage: 1988–2025

Coverage reflects the full annual datasets currently available.

Data Usage

For a selected country:

• No currency conversion is performed.
• Amounts remain in the domestic currency of the selected country.

Verification

• CPI data is manually sourced from the official statistical agencies listed above.
• Datasets are stored as static files within the project.
• Calculator logic reads directly from those stored annual index values.

For the full published CPI tables used by the calculator, see:

CPI Data Tables (by country)

Limitations

• CPI reflects a standardized basket of goods and services and may not reflect individual consumption patterns.
• Index methodologies differ slightly by country.
• Historical revisions by statistical agencies may alter previously published values.

If any discrepancy is identified between the published CPI tables and calculator results, the index values in the dataset govern.