The raw index doesn't take into account the cost of labour - how much people are paid to make the burger - which is likely to be much less in poorer countries - making the burgers much cheaper.
An adjusted index which takes into account the GDP of a country and divides it by the population pointed to the currency gap being much smaller in New Zealand with just a 2 per cent undervaluation by the Kiwi.
In this index Brazil was found to have the most overvalued currency while Egypt still remained the most undervalued.
Top three overvalued currencies
• Switzerland 25.5 per cent overvalued
• Norway 12 per cent overvalued
• Sweden 4 per cent overvalued
Most undervalued currencies
• Egypt 71.1 per cent undervalued
• Ukraine 69.5 per cent undervalued
• Malaysia 64.6 per cent undervalued
*based on the Big Mac Index raw data