Highest monthly inflation: 79,600,000,000%
Prices doubled every: 24.7 hours
The most recent example of hyperinflation, Zimbabwe's currency woes hit a peak in November 2008, reaching a monthly inflation rate of approximately 79 billion percent, according to the Cato Institute. Although the Zimbabwean government stopped reporting official inflation statistics during the worst months of the country's hyperinflation, the report uses standard economic theory (comparisons of purchasing power parity) to determine Zimbabwe's worst rates of inflation.
With prices almost doubling every 24 hours, just days after issuing a $100 million bill, the Reserve Bank issued a $200 million bill and capped bank withdrawals at $500,000, which at the time was equal to about $0.25 US. When the $100 million bill was introduced, prices soared, and reports from the country described that the price for a loaf of bread rose from $2 million to $35 million overnight. At one point, the government even declared inflation to be "illegal" and arrested the executives of companies for raising prices on their products.
The situation became so dire that shops in the country simply began refusing the currency and the US dollar, as well as the South African rand became the de facto medium of exchange. Inflation finally came to the end with direct intervention by the Reserve Bank of Zimbabwe that re-priced the currency, pegging it to the US dollar. The government also issued regulations that shut down the country's stock exchange.