The rate of zakat al-fitr if it is given in the form of meat
Question

Ibn al-Qayyim (may Allah have mercy on him) said that it is permissible to give zakat al-fitr in the form of meat, as he mentioned in I‘laam al-Muwaqqi‘een (3/12):
If their staple food is something other than grains, such as milk, meat or fish, they may give their zakat al-fitr in the form of their staple food, no matter what it is…
My question is: if I want to give meat, must I give 2.5 kilograms of meat, or should I work out the value of rice and the cost of a saa‘ of rice, then convert it into a cash value, and then buy meat with that cash value?
Praise be to Allah.Firstly: 
In fatwa no. 99327 we stated that it is permissible to give zakat al-fitr in the form of meat, for those whose staple food is meat. 
Secondly: 
There are hadiths from the Messenger (blessings and peace of Allah be upon him) which give the rate of zakat al-fitr as a saa‘ of food. If the Muslim chooses to give zakat al-fitr in the form of meat, or anything else that is weighed and not measured, then he should work out the amount of his zakat al-fitr by weight. 
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: 
But some have told us that a saa‘ of meat cannot be measured, so we say: If it is not possible to measure something, then we should resort to weighing it. 
End quote from ash-Sharh al-Mumti‘ (6/182) 
The scholars have stated the rate of zakat al-fitr, if it is given in the form of meat. It says in Haashiyat ad-Dasooqi al-Maaliki (5/36):
Zakat al-fitr is to given “by weight in the case of meat and the like” means meat and similar things, such as yoghurt, which are to be given in the form of five and one-third Baghdadi artaal. End quote.
A ratl (pl. artaal) is a unit of weight and also of measure. Many researchers have determined that the Baghdadi ratl is equivalent to 408 grams. 
See: Majallat al-Buhooth al-Islamiyyah, issue no. 39 and 59 
Based on that, zakat al-fitr in the form of meat is 2176 grams. 
It is well-known that giving the equivalent of the saa‘ in weight is also approximate, because the weight of a saa ‘ differs according to whatever is measured in this manner. So if the Muslim decides to err on the side of caution and give more than that, that is better. 
Ibn Qudaamah (may Allah have mercy on him) said: 
We have indicated that the saa‘ is equivalent to five and one  third Baghdadi artaal, and the ratl is originally a unit of measurement. In terms of weight, the scholars estimated it so that it may be known and transmitted to others. 
A number of scholars narrated from Ahmad that he said: I weighed the saa‘ and found it to be five and one third artaal of wheat. 
He also said: We took some lentils and used them as the standard, for they are the best thing that we have come across to be used as a standard for weighing, because they do not shift around. So we took a measure of lentils, then we weighed it and we found it to be five and one third artaal. 
So if the saa‘ is five and one third artaal of wheat and lentils, which are among the heaviest of grains, then other types of zakat al-fitr must be lighter than them, in which case if a person gives five and one third artaal of them, this will be more than a saa‘ … It is better for the one who gives something heavy by weight to err on the side of caution and add a little to it so that he may be certain that he has given a saa‘. 
End quote from al-Mughni (4/287) 
And Allah knows best.