The Indian rupee is the most undervalued currency in the world, based on the price of a Big Mac burger from local McDonald's outlet. India is the place where the 'Big Mac' turns out to be the cheapest in US dollar terms.

The purchasing power of the rupee is the highest in terms of the dollar value of the Big Mac, while the Big Mac value of the dollar is way down that of the Indian rupee, according to the Mac Index, published by The Economist.

The latest Big Mac index, which bases the purchasing power of various national currencies on their Big Mac value, finds the Swiss Frank as the world's most overvalued currency.

The rupee has remained the most undervalued currency ever since the currency was included in the index in July last year.

While the Big Mac is priced at $4.20 a piece in the US (as of 11 January 2012), it is priced at $6.81 in Switzerland and at $1.62 in India – the lowest price for the Big Mac in the world.

Though the Big Mac is not sold in India because it uses beef fillings, its Indian equivalent 'Maharaja Mac' costs much less than its US counterpart.

''The cheapest burger is found in India, costing just $1.62. Though because Big Macs are not sold in India, we take the price of a Maharaja Mac, which is made with chicken instead of beef,'' it added.

While the Big Mac may be representative in the sense that the product has a presence across the world, it need not be rightly priced to represent the true international value of the ingredients that go into its making.

However, since fast-food has a market across the world, the magazine thinks its 'burgernomics' makes sense.

''According to burgernomics, the Swiss franc is a meaty 62 per cent overvalued. The exchange rate that would equalise the price of a Swiss Big Mac with an American one is Swiss franc 1.55 to the dollar,'' as per the latest index.

 ''Nonetheless, our index suggests the rupee is 60 per cent undercooked. The euro, which recently fell to a 16-month low against the dollar, is now trading at less than euro 1.30 to the greenback,'' The Economist said.

The rupee, meanwhile, has depreciated by about 19 per cent over the last one last year, hitting a low of 54.30 against the US dollar on 15 December 2011.

The rupee continues to stay above 51 against the US dollar.