The Holocaust - Updated figures from Wolfgang Benz's Holocaust Encyclopedia for the Jewish death toll, by post-war European countries

Broader definitions include the two to three million Soviet POWs who died as a result of mistreatment due to Nazi racial policies, two million non-Jewish ethnic Poles who died due to the conditions of Nazi occupation, 90,000–220,000 Romani, 270,000 mentally and physically disabled killed in Germany's eugenics program, 80,000–200,000 Freemasons, 20,000–25,000 Slovenes, 5,000–15,000 homosexuals, 2,500–5,000 Jehovah's Witnesses and 7,000 Spanish Republicans, bringing the death toll to around 11 million. The broadest definition would include six million Soviet civilians who died as a result of war-related famine and disease, raising the death toll to 17 million.[7] A research project conducted by the United States Holocaust Memorial Museum estimated that 15 to 20 million people died or were imprisoned.[12] R.J. Rummel estimates the total democide death toll of Nazi Germany to be 21 million.

Reference 1: Death toll of Jews

Reference 2: Germany, Austria, Luxembourg, France, Belgium, Netherlands, Denmark, Norway, Italy, Albania, Greece, Bulgaria, Yugoslavia, Hungary, Czechoslovakia, Romania, Poland and Soviet Union.

Source: http://en.wikipedia.org/wiki/The_Holocaust