A few authentic hadiths regarding the amount of Fitrana are as follows:

1. Narration of Abdullah bin Umar:

Abdullah bin Umar narrates:

"The Messenger of Allah ﷺ made Sadaqat al-Fitr obligatory, one Sa' of dates or one Sa' of barley, on every slave, free man, male, female, young and old Muslim. And he ﷺ instructed that it (Sadaqat) should be paid before the Eid prayer."

(Bukhari: 1503, Muslim: 984)

2. Narration of Abu Sa'id Khudri:

Abu Sa'id Khudri states:

"During the time of the Noble Prophet ﷺ, we used to give Sadaqat al-Fitr on Eid al-Fitr day as one Sa' of food items (grains), which included dates, barley, raisins, and cheese (dried food made from milk)."

(Bukhari: 1510, Muslim: 985)

3. Narration of Ibn Abbas:

Ibn Abbas states:

"The Messenger of Allah ﷺ declared Sadaqat al-Fitr as a means of purification for the fasting person and a provision for the needy. Whoever pays it before the Eid prayer, it is an accepted charity, and whoever gives it after the prayer, it will be considered a regular charity."

(Abu Dawood: 1609, Ibn Majah: 1827)

Summary:

These hadiths clarify that:

The amount of Fitrana is 1 Sa', which can be given in dates, barley, raisins, cheese, or any other staple food.

If wheat is given, some narrations mention ½ Sa' (approximately 1.633 kilograms), as wheat is more filling compared to other grains.