How many Jewish people were left in the world after World War 2?

Between 1939 and 1945, the worldwide Jewish population decreased according to the Jewish Virtual Library from 16.7 to 11 million. According to the Jewish World Almanac however the total number remained practically stable between 1933 and 1948 at a little above 15 million. Looking at the latter publication's figures for Europe alone, this number remains almost unchanged as well, which seems improbable. One of the Almanac's editors later said that the post-war figures had been an estimate and that the real figure probably was closer to 12 million.

So 11 to 12 million is probably correct. Today's number of 14 million is largely and equally divided over two groups, in Israel and the US.