South Africa is second from the bottom on the Economist magazine's latest "Big Mac Index", which measures how global currencies perform against each other.
The index compares the prices of a McDonald's burger across the world and is a light-hearted and not-quite precise way of measuring whether currencies are under- or over-valued.
South Africa's position above India, but below around forty other countries, means the rand is under-valued against the US dollar and the Euro.
This means the currency is not performing as well as it should be.
Economist Dawie Roodt said: "The value of the currency is quite weak and actually that means we are all a little bit poorer than what we're supposed to be."
Roodt said that his own invention, the "Big Bang Index", compares the price of prostitution in different countries and supports the results found in the Economist's "Burgernomics".
The most over-valued currencies belong to countries such as Sweden, Norway and Switzerland.