What is the correct amount of the obligatory mudd for making up missed Ramadan fasts, is it 750 grams or a sa' – i.e., approximately one and a half kilograms?

The gist of the fatwa: The website's fatwa regarding the obligation of one sa' for the delayed expiation (fidyah) is correct. Ibn Baz stated that a half sa' (i.e., two mudds), which is approximately 1.5 kilograms, is obligatory, and this aligns with the statement of Al-Thawri.

Al-Nawawi mentioned that the view of the majority, which is also the Shafi'i madhhab, obligates one mudd of food for each day. This is the view of Ibn Abbas, Abu Hurayrah, Ata', Al-Zuhri, Malik, Al-Thawri, Ahmad, and Ishaq, except that Al-Thawri said the expiation is two mudds for each day.

Al-Majd Ibn Taymiyyah said in "Al-Muharrar": "Feeding a poor person is estimated as one mudd of wheat, or half a sa' of dates or barley, here and in every instance of expiations."

The Permanent Committee issued a fatwa stating that the feeding should be "for each poor person one mudd of wheat, or half a sa' of other types."

Ibn Qudamah said in "Al-Mughni": "Abu Hurayrah said: He feeds one mudd of whatever type he wishes," then he used this to support the Hanbali madhhab, stating that one mudd of wheat takes the place of half a sa' of other types, and that sufficiency with one mudd is the saying of Ibn Umar, Ibn Abbas, Abu Hurayrah, and Zayd.

Half a sa' is more cautious than one mudd, and this is the view of Abu Hanifah. Ibn Baz adopted this view for all categories as a precaution, and Ibn Uthaymeen also adopted it.

In summary: The fatwa is correct and consistent with what a group of Companions and Tabi'in issued, and it has its evidence from the Sunnah. It is the madhhab of Malik, Al-Shafi'i, and others. Whoever wishes to be cautious by giving half a sa' may do so.