The Amount of Fidyah for Not Fasting
Question

What is the amount of Fidyah that is mentioned in the verse on fasting?.
Praise be to Allah.Who must pay the Fidyah?
If Ramadan comes and a person is unable to fast because he is elderly or sick with no hope of recovery, then he is not obliged to fast because he is unable to do so. So he should not fast and he should feed one poor person for each day . 
Allah says (interpretation of the meaning): 
“O you who believe! Observing fasts is prescribed for you as it was prescribed for those before you, that you may become pious.
[Observing fasts] for a fixed number of days, but if any of you is ill or on a journey, the same number (should be made up) from other days. And as for those who can fast with difficulty, (e.g. an old man), they have (a choice either to fast or) to feed a poor person (for every day). But whoever does good of his own accord, it is better for him. And that you fast is better for you if only you know.” [Al-Baqarah 2:183-184]
Al-Bukhari (4505) narrated that Ibn `Abbas (may Allah be pleased with him) said: “This has not been abrogated. It refers to old men and old women who are not able to fast, so they should feed a poor person for each day.” 
Ibn Qudamah (may Allah have mercy on him) said in Al-Mughni (4/396): 
“If fasting is too difficult for an old man or an old woman, and will cause them intense hardship, then they are allowed not to fast, and they should feed one poor person for each day. If they are also unable to feed a poor person, then they do not have to do anything, for “Allah burdens not a person beyond his scope” [Al-Baqarah 2:286]. If a sick person has no hope of recovery, he is allowed not to fast, and he should feed one poor person for each day, because he comes under the same ruling as an old man.” 
In Al-Mawsu`ah Al-Fiqhiyyah (5/117) it says: 
“The Hanafis, Shafi`is and Hanbalis agreed that the Fidyah for not fasting should be paid when there is no hope of making up the missed fasts because of old age which makes a person unable to fast, or sickness from which there is no hope of recovery, because Allah says (interpretation of the meaning): “And as for those who can fast with difficulty, (e.g. an old man), they have (a choice either to fast or) to feed a poor person (for every day).” [Al-Baqarah 2:184] What is meant is those for whom it is too difficult to fast.” 
Shaykh Ibn `Uthaymin (may Allah have mercy on him) said in Fatawa As-Siyam (p.111): 
“It is essential to note that the sick may be divided into two categories: 

Those for whom there is the hope of recovery, such as those with temporary sickness from which there is the hope of recovery. In this case the ruling is as Allah says (interpretation of the meaning): “but if any of you is ill or on a journey, the same number (should be made up) from other days” [Al-Baqarah 2:184]. All they have to do is wait until they are better, then fast. If it so happens that the sickness continues and the person dies before recovering, then there is no sin on him, because Allah has only enjoined him to make it up from other days, but he died before those other days came. This is like a person who dies in Sha’ban before Ramadan begins – so it should not be made up on his behalf. 
Cases where sickness is ongoing, such as cancer – Allah forbid – kidney disease, diabetes and similar chronic diseases where there is no hope of recovery. These people are allowed not to fast in Ramadan, but they have to feed one poor person for each day, like old men and women who are unable to fast, so they may not fast and should feed one poor person for each day. The evidence for that in the Quran is the verse in which Allah says (interpretation of the meaning): “And as for those who can fast with difficulty, (e.g. an old man), they have (a choice either to fast or) to feed a poor person (for every day).” [Al-Baqarah 2:184]

The Amount of Fidyah for not fasting
With regard to the manner of feeding, one has the choice between giving each poor person half a Sa` of food such as rice and the like (i.e., approximately one and a half kilograms) or making food and inviting the poor to eat. 
Al-Bukhari (may Allah have mercy on him) said: “As for an old man who is unable to fast, after Anas (may Allah be pleased with him) grew old, for one or two years he fed a poor person with bread and meat and he did not fast.” 
Shaykh Ibn Baz (may Allah have mercy on him) was asked about an elderly woman who was unable to fast – what should she do? 
He (may Allah have mercy on him) replied: 
“She should feed one poor person for each day, giving half a Sa` of the local staple food, such as dates, rice, etc, which is equivalent to approximately one and a half kilograms. This was stated by a number of the companions of the Prophet (peace and blessings of Allah be upon him), such as Ibn `Abbas (may Allah be pleased with him). If she is poor and is unable to feed a poor person, then she does not have to do anything. This expiation may be given to one or more people at the beginning of the month or in the middle or at the end. And Allah is the Source of strength.” (Majmu` Fatawa Ibn Baz (15/203) 
Shaykh Ibn `Uthaymin (may Allah have mercy on him) said in Fatawa As-Siyam (p. 111): 
“The sick person who has an ongoing sickness, and elderly people, both male and female, who are unable to fast, must feed one poor person for each day, whether that is by giving this food to the poor or by inviting the same number of poor people as days in the month to a meal, as Anas ibn Malik (may Allah be pleased with him) used to do when he grew old. He would gather together thirty poor people and that was instead of fasting for a month.”  
The Standing Committee (11/164) was asked about the giving of food by one who is unable to fast in Ramadan such as old men, old women and the incurably sick. 
They replied: 
“If a person is unable to fast in Ramadan because of old age, such as elderly men and women, or it is very difficult for them to fast, then they are allowed not to fast, but they have to feed one poor person for each day, giving half a Sa’ of wheat, dates or rice etc, the same as he gives to his own family. The same applies to a sick person who is unable to fast or for whom it is very difficult to fast, and there is no hope of recovery for him, because Allah says (interpretation of the meaning):
“Allah burdens not a person beyond his scope.” [Al-Baqarah 2:286]
“and [Allah] has not laid upon you in religion any hardship.” [Al-Hajj 22:78] 
““And as for those who can fast with difficulty, (e.g. an old man), they have (a choice either to fast or) to feed a poor person (for every day).”” [Al-Baqarah 2:184]”
And Allah knows best.