At the recent EU summit, politicians declared "up to 200 billion EUR" loans to IMF to strengthen the defense of the Euro.
150 billion EUR should come from the eurozone member countries, and 50 billion EUR from the other EU states.
It's quite easy to find out where these numbers come from: 150 billion EUR / (eurozone GDP / EU GDP) = 202.45 billion EUR.
However, the UK veto changes slightly this calculation.
First some basic statistics (source: Wikipedia):
EU GDP = 12,268,387 million EUR
EU GDP less UK = 10,471,804 million EUR
Eurozone GDP = 9,089,966 million EUR
non-eurozone GDP = 3,178,421 million EUR
non-eurozone GDP less UK = 1,381,838 million EUR
non-eurozone GDP less UK / non-eurozone GDP = 43,48%
Hence, the 50 billion EUR non-eurozone contribution, will most probably be reduced by some 57%:
50 billion EUR * 43.48% = 21.74 billion EUR
Assuming no other country backs off from the plan, we should expect that the IMF loans will total:
150 + 21 = 171 billion EUR
BTW: A Polish newspaper "Gazeta Polska codziennie" suggests the Polish contribution to the IMF loans will equal 100 billion PLN or 22.22 billion EUR. I don't understand where this number comes from. I'd assume, Polish contribution would be equal to 21.74 billion EUR * (Polish GDP / non-eurozone GDP less UK) or 5.57 billion EUR * 4.50 EURPLN = 25.08 billion PLN.