The Simon Wiesenthal Center in its "36 Questions About the Holocaust" says there were about 5,860,000 Jews killed in the Holocaust and it breaks it down:
http://motlc.wiesenthal.com/site/pp.asp?c=gvKVLcMVIuG&b=394663Yehuda Bauer, a highly respected Holocaust scholar, decreased the number of Jewish victims killed in Nazi death and concentration camps, but the total figure includes Jews killed outside the camps, such as the many massacres that took place. So the lowest total figure is still over 4 million to a high of almost 6 million. There are databases with the names of about 3 million people killed, so to say that only 1.5 million or so were killed is, at the very least, ignorance.
The Wikipedia article cites several sources here: "Since 1945, the most commonly cited figure for the total number of Jews killed has been six million. The Yad Vashem Holocaust Martyrs' and Heroes' Remembrance Authority in Jerusalem, writes that there is no precise figure for the number of Jews killed,[317] but has been able to find documentation of more than three million names of Jewish victims killed,[318] which it displays at its visitors center. The figure most commonly used is the six million attributed to Adolf Eichmann, a senior SS official.[319]
Early calculations range from about 4.2 to 4.5 million in The Final Solution (1953) by Gerald Reitlinger (arguing against higher Russian estimates),[320] and 5.1 million from Raul Hilberg, to 5.95 million from Jacob Lestschinsky. Yisrael Gutman and Robert Rozett in the Encyclopedia of the Holocaust estimate 5.59–5.86 million.[321] A study led by Wolfgang Benz of the Technical University of Berlin suggests 5.29–6.2 million.[322][323] Yad Vashem writes that the main sources for these statistics are comparisons of prewar and postwar censuses and population estimates, and Nazi documentation on deportations and murders.[322] Its Central Database of Shoah Victims' Names currently holds close to three million names of Holocaust victims, all accessible online. Yad Vashem continues its project of collecting names of Jewish victims from historical documents and individual memories.[324]
Hilberg's estimate of 5.1 million, in the third edition of The Destruction of the European Jews, includes over 800,000 who died from "ghettoization and general privation"; 1,400,000 killed in open-air shootings; and up to 2,900,000 who perished in camps. Hilberg estimates the death toll of Jews in Poland as up to 3,000,000.[325] Hilberg's numbers are generally considered to be a conservative estimate, as they typically include only those deaths for which records are available, avoiding statistical adjustment.[326]"
http://en.wikipedia.org/wiki/The_Holocaust#Jewish
