There is no precise figure for the number of Jews killed in the Holocaust. The figure commonly used is the six million quoted by Adolf Eichmann, a senior SS official. Most research confirms that the number of victims was between five and six million. Early calculations range from 5.1 million (Professor Raul Hilberg) to 5.95 million (Jacob Leschinsky). More recent research, by Professor Yisrael Gutman and Dr. Robert Rozett in the Encyclopedia of the Holocaust, estimates the Jewish losses at 5.59–5.86 million, and a study headed by Dr. Wolfgang Benz presents a range from 5.29 million to six million.

The main sources for these statistics are comparisons of prewar censuses with postwar censuses and population estimates. Nazi documentation containing partial data on various deportations and murders is also used. We estimate that Yad Vashem currently has somewhat more than four million names of victims that are accessible. This figure is based primarily on some two million Pages of Testimony, which often contain information about more than one Jew who perished in the Holocaust. As of early June 1999, more than 1.6 million Pages of Testimony have been computerized. In addition, we have thousands of documents containing names from the Holocaust era, many of which are those of victims. This body of documentation has yet to be fully researched and added to our computerized database. Eventually we hope, through our computerization project, to provide as much information as possible about each victim.

Because there are no hard and fast statistics for all the Jews murdered in countries under Nazi domination, and due to frequent border changes before, during, and after the war, it is difficult to enumerate the victims by country. The following information is taken from the Encyclopedia of the Holocaust, based on research at Yad Vashem. The Encyclopedia explains the figures presented here for each country.