Fitrana (Zakat ul Fitr) is incumbent on every Muslim who possesses one saa’* of food which is not needed as a basic necessity for themselves self or their family for the duration of one day and night.
“"The quantity is described the Prophet (SAW) as one saa’ of food. One saa’ is equivalent to four madd. A madd is the amount that can be scooped up when one puts their hands together.""
Ibn `Abbas (may Allah be pleased with him) reported:
[Abu Dawud and Ibn Majah]