About, data & copyright

• Site, code and texts: © 2026 Rogzy, released under the MIT licence. You may reuse them, including commercially, as long as you keep the copyright and licence notice.
• Banknote images: scans from David St-Onge’s banknote collection, shown here with his permission. They are not covered by the MIT licence: the download buttons are for personal and educational use; any other reuse needs his permission.
• The banknote designs belong to the central banks and governments that issued them. Almost all are long withdrawn. A few recent ones (Lebanon 2021, Venezuela 2020) may still be legal tender; they are shown for history and education, not for reproduction.
• Third parties: book covers from the Open Library Covers API, flags from flagcdn, charts drawn with Chart.js and texts rendered with Marked (both MIT).

What counts as a hyperinflation

We use Phillip Cagan’s definition (1956), the one most economists use: a hyperinflation begins in the month prices rise 50% or more, and ends when the monthly rate falls below 50% and stays there for at least a year. 50% a month is about 13,000% a year.

The collection holds 20 hyperinflations and one contrast case: Turkey 1990–2005 had decades of high inflation but never reached 50% in a month. It is labelled “Not a hyperinflation” and is not counted.

“Worst month”

The highest price rise in a single month, taken from the reference table of Hanke & Krus (World Hyperinflations, 2012) unless the period’s page says otherwise. It is never an annual rate: mixing the two makes periods impossible to compare. Two exceptions are named on their pages: Venezuela (National Assembly estimate) and Lebanon (an implied rate: Steve Hanke inferred it from the black-market exchange rate, because official prices understated it).

“When” and the period dates

“When” is the worst month. The years on each card cover the wider crisis; the exact months above 50% are given in each history, under Key figures. Some countries had two separate episodes (Peru, Zaire).

“Currency reform”

How the old money was replaced or how many zeros were removed, for example 1 forint = 4×10²⁹ pengő. It is the clearest single measure of how much a currency lost.

The charts

• They show how many units of the currency one US dollar bought, on a logarithmic scale (each step up is ten times more) and a true time axis.
• When a currency was redenominated, later values are converted back into the original unit, so removing zeros never looks like a recovery. The chart says so in its subtitle.
• Many historical series exist only as scattered figures. Charts built from them are marked “approximate”: they show the shape, not exact values. The figures to quote are in the texts, each with its source.
• Where no trustworthy series exists (Angola, the Philippines), there is no chart rather than a guess.

The banknotes

Each label is read off the note itself: denomination and the date printed on it. A note printed after the period, or in a different currency, says so.

The histories

Every history is written from a knowledge base in which each figure carries its source. Anything we could not verify is left out of the page, not softened. Sources are listed at the bottom of each history.

Found an error?

Historical figures differ between sources, and we will have made mistakes. Please open an issue on GitHub with the page, the figure and your source.

• Hanke, S. H. & Krus, N. (2012), World Hyperinflations, Cato Institute Working Paper no. 8: episodes, worst months and doubling times.
• Cagan, P. (1956), “The Monetary Dynamics of Hyperinflation”, in M. Friedman (ed.), Studies in the Quantity Theory of Money: the 50% definition.
• Hanke, S. H. (2020), “Lebanon Hyperinflates”, Cato Institute: Lebanon’s implied rate.
• Wikipedia articles on each currency and crisis, cited on each page with the date they were read.
• Fergusson, A. (1975), When Money Dies; Bresciani-Turroni, C. (1931, English translation 1937), The Economics of Inflation: Germany and Austria.

• This site is educational. It is not financial, investment, legal or tax advice, and nothing on it predicts what any currency will do.
• Figures are given as reported by the cited sources, which sometimes disagree. We pick one, name it, and note serious disagreements; the information is provided as is, without warranty (MIT licence).
• The banknotes are historical items shown for study. They are not for sale here, and almost all of them stopped being money long ago.
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