.....approximately 825,000 Jews living in Hungary in 1941....
A grossly exaggerated figure.
According to the 1941 census of enlarged Hungary, the Jewish population was 725,007, that is, registered members of the Jewish community.
In addition the census found 58,329 so-called "Christian Jews", of whom 34,435 were subject to the anti-Jewish laws. All except 6,038 of the "Christian Jews" lived in Trianon Hungary, and 36,362 lived in Budapest alone.
Adding the "Christian Jews" subject to the anti-Jewish legislatiuon to the registered Jews yields a total of 759,447 persons subject to persecution as Jews. However, since the majority of the "Christian Jews" lived in Budapest, it is unlikely that many of them were deported.
Let us assume that the figure of around 255,000 Jewish survivors is correct. That figure would not include "Christian Jews, since such persons were considered Jewish only by the wartime Hungarian authorities, not by the Jews themselves.
Accordingly, the figure of 255,00 Jewish survivors must be compared to the 1941 census figure of 725,000 Jews. Subtracting 255,000 from 725,000 leaves a maximum figure of 470,000 who could have perished. The actual total is likely to be less than that, since the figure of 255,000 survivors would include only those who were not deported or who survived deportation and returned; it would not include surviving deportees who did not return to their former places of residence.
And the figure of 225,000 survivors might well be an underestimate. For example, the chapter on Hungary in the book "Dimension des Voelkermords" estimates that 293,000 of the 1944 Jewish population of enlarged Hungary survived. That would reduce the maximum number of victims to 432,000.
That is over 100,000 less than the grossly exaggerated figure of 563,000 dead postulated by Paolosilv.