Data sources, files and licences
Every reference figure the calculators use comes from an official publisher, is stored unmodified in a dated file, and is served from this website — the same file for every visitor.
Exchange rates (ECB)
The currency converter uses the European Central Bank’s euro foreign exchange reference rates: 29 currencies against the euro, every TARGET business day from 1999-01-04 to 2026-10-07. Rates are stored exactly as published. Cross rates between two non-euro currencies, and rates carried forward over weekends and holidays, are derived by MoneyOtter and labelled as such. ECB usage policy (read 2026-10-07): "All publicly available ESCB statistics may be reused free of charge on the condition that the source is quoted (e.g. “Source: ECB statistics.”) and that the statistics (including metadata) are not modified." Free reuse applies "irrespective of any subsequent commercial or non-commercial use". MoneyOtter labels cross rates and carried-forward rates as derived, never as ECB figures.
| File | Covers | SHA-256 |
|---|---|---|
| latest.json | Last five business days | — |
| manifest.json | Index of all files with hashes | — |
| history-2026.json | 2026-01-02 to 2026-10-07 (196 days) | 98447c3f7c0c5376… |
| history-2025.json | 2025-01-02 to 2025-12-31 (255 days) | 466757b5183a5eb1… |
| history-2024.json | 2024-01-02 to 2024-12-31 (256 days) | b1590a0f0d620744… |
Yearly files exist for every year from 1999; the manifest lists them all. Source: European Central Bank, euro foreign exchange reference rates. Attribution: “Source: ECB statistics”. ECB statistics usage policy.
Consumer price indexes
The inflation calculator uses national consumer price indexes, stored exactly as each statistics office publishes them. A series is offered only once its licence is confirmed for reuse.
| Series | Publisher | Frequency | Data | Licence |
|---|---|---|---|---|
| au | Australian Bureau of Statistics | quarterly | 1948-Q3 to 2026-Q2 | Creative Commons Attribution 4.0 International (CC BY 4.0) |
| au-monthly | Australian Bureau of Statistics | monthly | 2024-04 to 2026-08 | Creative Commons Attribution 4.0 International (CC BY 4.0) |
| ca | Statistics Canada | monthly | 1914-01 to 2026-08 | Statistics Canada Open Licence |
| de-hicp | Eurostat | monthly | 1996-01 to 2026-09 | Eurostat reuse policy (Commission Decision 2011/833/EU) |
| ea-hicp | Eurostat | monthly | 1996-01 to 2026-09 | Eurostat reuse policy (Commission Decision 2011/833/EU) |
| gb | Office for National Statistics | monthly | 1988-01 to 2026-08 | Open Government Licence v3.0 |
| gb-longrun | Office for National Statistics | monthly | 1947-06 to 2026-08 | Open Government Licence v3.0 |
| us | U.S. Bureau of Labor Statistics | monthly | 1913-01 to 2026-08 | Public domain (U.S. federal government work, 17 U.S.C. §105) |
Not yet offered while the licence is confirmed: de (Statistisches Bundesamt (Destatis)).
VAT, GST and sales tax rates
The VAT calculator and the rates table use 107 rows covering countries, US states and Canadian provinces, checked on 2026-10-07. Each row lists its official source; 92 rows were read on an official authority page and the rest are marked provisional until they are. US rows hold the state base rate only, because local rates vary by address. standard-rates.json
Currency pegs
Some currencies are fixed to the US dollar or the euro by their central bank. The converter uses these official parities, labelled as derived, for: AED (AED per 1 USD); SAR (SAR per 1 USD); QAR (QAR per 1 USD); OMR (USD per 1 OMR (central bank states 'USD 2.6008 per RO'; inverse ~0.3845 OMR per USD is derived, not stated)); BHD (BHD per 1 USD); HKD (HKD per 1 USD); XOF (XOF per 1 EUR (BCEAO writes '655,957 FCFA = 1 euro')); XAF (XAF per 1 EUR (BEAC writes '1EUR = 655,957 F.CFA')); BAM (BAM per 1 EUR (law: 1 KM = 0.511292 EUR)). pegs.json
Reusing our data
You’re welcome to use these files. The underlying statistics belong to their publishers and are reused under the licences above; please credit them as they ask (for example “Source: ECB statistics”). Our compilation is offered under CC BY 4.0 with credit to MoneyOtter. Files may change as publishers release new data; every change that affects a figure is dated in the changelog. Spotted a problem? Email errors@moneyotter.com.
The JSON files are not web pages and are excluded from search indexing.