This post is to understand the concept of FITRA and how to calculate it.
FITRA is must on a Muslim who is an adult and sane, be it he/she is neither unconscious, poor, slave of another. It is obligatory on him/her that he/she should on his/her own behalf as well as on the behalf of the dependents on him/her, should pay the price of the food grains which he/she uses as staple food amounting to be three kilograms in weight. Fitra becomes incumbent after sighting the new moon of Shawwal.
In case there is a guest at your place, and is your guest on the eve of Eid-ul-Fitr, his/her Fitra is WAJIB (MUST) on, if he/she is not paying it on their own.
CALCULATIONS OF FITRA :-
It is confusing for the people to find the cost of the commodity as the prices of the food grains are of vast range. In this case you have to calculate the mean cost of the grains and then calculate to the amount on three kilograms.