All of the following information was translated originally from Durr-ul-mukhtar, and from Ibni Abidin’s Radd-ul-mukhtar, which is an explanation of the former:
By the first light of the morning of the first day of ‘Iyd of Ramadan, to give the Fitra becomes wajib for every free Muslim who has property or money as much as the amount of nisab in addition to his indispensable possessions and debts. It does not become wajib before or after that time. The property that is to be included in the calculation of nisab for fitra and Qurban does not necessarily have to be intended for trade, nor does one have to have had it for one year. The condition is that one should have property as much as the amount of nisab by the time morning prayer becomes performable on the first day of ‘Iyd. Giving the fitra is not wajib for a person who receives the amount of nisab or who is born, or becomes a Muslim after that moment. It is necessary also for the safari (traveler) to give the fitra. It is also permissible to give it during Ramadan-i-Sharif, before Ramadan, or after the ‘Iyd. Furthermore, if a person died before giving the fitra, zakat, kaffarat or something he vowed, and if he did not will it in his last request that it must be given, it is permissible for one of his inheritors to give it to the poor out of his own property, [not necessarily out of the dead person’s property]. But the inheritor does not have to give it. If he willed that it must be given, it is necessary to give it out of a third of the property he has left behind. His will is not executed if he has not left property. There will be more blessings if the fitra is given before the ‘Iyd prayer. It cannot be given before Ramadan in Shafi’i Madhhab and before ‘Iyd in the Madhahib of Maliki and Hanbali. As one person’s fitra can be given to one or more poor people, so one poor person can be given the fitras of several people. If a small child or an insane person has property, his fitra is also given out of his property. If their guardian does not give it, the child gives his past fitra when he grows up and the insane person gives his when he recovers. If a child below the age of puberty does not have property, its father gives its fitra together with his own fitra. That is, he gives it if he is rich. He does not have to give the fitra for his wife or older children. But he attains blessings if he gives it.
It is written in Durr-ul-mukhtar and Radd-ul- mukhtar, “If a person gives the fitra for someone else out of his own property, it becomes permissible if the latter has commanded it in advance. If he has not given it with the latter’s command, it does not become permissible even if he consents afterwards. If he has given it out of the latter’s property, it becomes permissible when the latter gives the consent. A man can give the fitras of the people he is supporting in his home without their advice. If one commands one’s wife [or someone else] to give one’s fitra, too, and if she (or he) mixes her (or his) wheat with one’s wheat without one’s permission and gives the mixture to the poor, she (or he) will have given only her (or his) fitra. For according to Imam-i-azam she (or he) will have used the wheat by mixing the two amounts of wheat with each other, and thus the wheat will become her (or his) property. But it does not become her (or his) property according to the two imams. If she (or he) has mixed them with one’s permission, one’s fitra also will have been given according to Imam-i-azam, too (rahmatullahi ta’ala ‘alaihim ajmain). If the act were done the other way, the wife’s fitra would have been given, too. For it is permissible for the husband to give the wife’s fitra as a kindness out of his own property without her permission. He can either mix the fitras of his wife and other household and give them without their permission, or weigh the wheat or gold equal to their total at once and give it to one or more poor people. But it is circumspect to prepare them separately and then mix them or give them separately.”
If one loses one’s property after having had the amount of nisab, that is, after fitra and Qurban having become wajib and hajj having become fard, one is not absolved from them. But zakat and ‘ushr are forgiven since the property has left one’s possession. But these are not forgiven, either, if one purposely disposes of it.
He who has the nisab of fitra and Qurban is called rich. It is wajib for him to give fitra. And if he is mukallaf, which means discreet, pubert and settled (not traveling), it is also wajib to perform the Qurban only for himself. It is haram for him to take zakat, and wajib to support his poor male relatives who cannot work and his poor mahram female relatives.
Basic needs include a house, a month’s food, three suits each year, underwears, things and gadgets used in the house, servants, means of transportation, books on one’s profession, whatever their value, and one’s debt. They do not have to exist. If they exist they are not included in the calculation of nisab for zakat, fitra and Qurban. Those possessions that are not intended for trade and are more than one’s need, one’s houses rented out, ornamental things in one’s house, carpets that are not laid on the floor, spare furniture that is not used, and tools of arts and trade are not considered as necessary property in this respect. They are included in the calculation of nisab for fitra and Qurban. If the house one is living in is big, it is sahih that the spare rooms that one does not use are not included in the nisab. See the beginning of chapter 4, which is about Performing the Qurban.
For fitra, half a sa’ of wheat or wheat flour is given. Or one sa’ of barley or dates or raisins is given. In Hanafi Madhhab, at times when wheat, barley and flour are abundant it is better to give their equivalents in gold and silver. During times of scarcity it yields more thawab to give these things themselves. In Hanafi Madhhab sa’ is (the volume of) a container with the capacity of one thousand and forty dirhams of millets or lentils. One sa’ is four muds, that is, four menns. Mud and menn are equal and are two ritls. One ritl is a hundred and thirty dirham-i shar’i or 91 mithqal, so one sa’ is  mithqals, or  dirhams, that is 3500 gr. of lentils. Since barley is lighter than wheat and wheat is lighter than lentils, a container that is filled with one thousand and forty dirhams of barley is larger than one sa.’ But it will be circumspection to call it one sa.’ It will be circumspection to give 364 mithqals, or five hundred and twenty  dirhams, which is seventeen hundred and fifty  grams, of wheat instead of half a sa.’ Thus a little more will have been given. For, half a sa’ of wheat is lighter than 364 mithqals, or five hundred and twenty dirhams. I, the faqir -Husain Hilmi Isik- experimented by using a balance and a cylindrical glass measuring jug, and found out that a hundred grams of lentils is a hundred and twenty cubic centimeters. Accordingly, one sa’ is equal to four liters plus one-fifth libre [4.2 liters].
In the Madhahib of Shafi’i, Maliki and Hanbali, to give the fitra is fard for a person who has a day’s food, and of whether wheat or barley it is always necessary to give one sa.’ In Shafi’i Madhhab one sa’ is one-third of a menn less than three menns. One menn is two ritl- i-Iraqi, or 260 dirhams. Then, one sa’ is six hundred and ninety-four  dirhams, which is written in Al Anwar. In other words, it is one thousand, six hundred and eighty  grams. For in Shafi’i Madhhab a dirham is 2.42 grams. One mud is two-third a menn, which is equal two 173 dirhams plus a third dirham. Then, one sa’ is four muds. In Shafi’i it is not permissible to give gold or silver equivalent of wheat or barley. It is written in Shamsaddin Ramli’s fatwa that it is permissible to follow Hanafi and give the wheat’s equivalent in silver instead of the wheat itself. The Madhahib of Maliki and Hanbali are the same as Shafi’i Madhhab in this respect, and so one sa’ is five ritls plus one-third a ritl, that is, 694 dirham-i-shar’i, or 1680 grams. These amounts have been stated clearly in the books Kimya-yi-se’adet and Manahij-al ibad ilal maad. The Turkish translation of the Arabic lexical book Kamus wa Okyanus states about the word Sa’: “Sa’ is a measure of capacity that contains four muds of lentils. One mud, an amount of two handfuls, is equal to two ritls in Hanafi Madhhab. Accordingly, one sa’ is eight ritls. In Shafi’i Madhhab one mud is one plus one-third ritls, and so one sa’ is five plus one-third ritls in that Madhhab.” And it states about the word Menn: “Menn, which means batmann, is two ritls in every Madhhab.”
A person who does not fast because of a good excuse has to give the sadaqa fitr.
Because the sadaqa fitr is small, it is given in silver. It is written in the book Jawhara, “When giving the sadaqa fitr, instead of wheat or barley, its value can be given in gold or silver, in fulus, that is, metal coins [and paper bills], or in any other kind of property.” And it is written in Durr-ul-mukhtar, “Its value is given in gold and silver.” To explain these statements, Ibni Abidin says, “The book Jawhara says that fulus and uruz, that is, kinds of property, can be given, yet when ‘value’ is said gold and silver are usually meant. Also Zeylai (rahmatullahi ta’ala ‘alaih) conveys that it is better to give its value in gold or silver.” Then, one should follow the words of the majority and give the fitra in gold or silver. Silver money is not in use now. And the value of paper money has been made dependent upon that of gold. Therefore, the value of silver with respect to the currency is below its value in the Sharia. It is given with its value according to the currency so that it will be to the advantage of the poor. In case it is difficult to give them, one should give half a sa’ [1750 grams] of wheat or flour instead of giving other property or paper money. One may also give paper money instead of gold by following the facility we have described in the first chapter. In the Madhahib of Maliki and Hanbali it is better to give dates, in Shafi’i, it is better to give wheat, and in Hanafi it is better to give what is most valuable.
If it is difficult also to give wheat or flour, one may give bread or corns of equal value. To give bread and corns, not their weight but their cost or value is considered.