The standard definition of hyperinflation comes from Phillip Cagan's 1956 study: a monthly inflation rate exceeding 50% — which compounds to roughly 130x prices in a single year. Applying that bar, Steve Hanke and Nicholas Krus catalogued 56 hyperinflation episodes in their Cato Institute working paper World Hyperinflations (2012). Two episodes dominate the popular imagination: Weimar Germany in 1923 and Zimbabwe in 2008.
After World War I, Germany faced enormous reparations and financed its deficits almost entirely by printing money. When France occupied the Ruhr industrial region in 1923 and the government printed marks to pay striking workers, prices exploded. In October 1923 monthly inflation reached nearly 30,000%, with prices doubling roughly every 3.7 days; by November, one US dollar traded for about 4.2 trillion paper marks. Workers collected wages in wheelbarrows; banknotes were used as kindling and wallpaper.
Nobel laureate Thomas Sargent, in his classic study The Ends of Four Big Inflations, highlighted the most striking fact: the inflation stopped almost overnight. In November 1923 Germany introduced the Rentenmark, backed by land assets, and — crucially — established an independent central bank barred from financing government deficits. Prices stabilized within weeks. It was not the new currency itself but the credible change in fiscal and monetary regime that flipped expectations.
Zimbabwe's inflation spiraled through the 2000s as land reform collapsed agricultural exports and chronic deficits were monetized. Official statistics put annual inflation at 231 million percent in July 2008 — after which the government simply stopped publishing numbers. Hanke and Krus estimate that in November 2008, monthly inflation hit 79.6 billion percent (7.96 × 10¹⁰%), with prices doubling about every 24.7 hours — the second-worst hyperinflation ever recorded, behind only Hungary in 1946. The central bank famously issued a 100-trillion-dollar banknote. Stability returned only in 2009, when Zimbabwe abandoned its currency in favor of the US dollar and South African rand.
Separated by 85 years, the two disasters followed the same script: government spending far beyond revenue, a central bank forced to print the difference, and a public that lost faith in the currency and fled into goods — making inflation self-accelerating. Both ended the same way too: cut the printing press loose from the deficit and rebuild monetary credibility. By comparison, the worst US inflation of the past century — about 15% in 1980 — is trivial. Yet even mild inflation compounds: try the inflation calculator to see how much purchasing power ordinary 2–3% inflation erodes over a few decades.