Question Summary:
What is the minimum distance of travelling required to be eligible for performing Qasar?

Question Detail:

 
Please provide me with the minimum distance required to  traveled to be eligible for performing qasar wa jama wrt all madad.

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
If one intends to travel a minimum distance of 77.8 (78) km or more, he will be regarded as a Musafir (traveller) once he leaves the housing area of his town. In that situation he will have to perform Qasar Salah.  
And Allah Ta’āla Knows Best
Abdullah ibn Mohammed Aijaz
Student Darul Iftaa
Baltimore, USA
Checked and Approved by,
Mufti Ebrahim Desai.
 
 
 الأصل للشيباني ط قطر (1/ 231)
قلت: أرأيت المسافر هل يقصر الصلاة في أقل من ثلاثة أيام؟ قال: لا. قلت: فإن سافر مسيرة ثلاثة أيام فصاعداً؟ قال: يقصر الصلاة حين يخرج من مصره
 Fatawa Mahmudiyyah V.7/PG.479 
Ahsanul Fatawa V.4/PG.15