MOST currencies are under-valued against the US$ Dollar – Russian Rouble is the most undervalued

by xmansiphone

Source: the big mac index by The Economist

Tools: GitHub and Numbers

The Big Mac index is essentially based on the concept of Purchasing Power Parity and thus compares the cost of the McDonalds big mac (made using almost the same ingredients in 100+ countries) in different countries to get an idea of the discrepancy in exchange rates.