Question: What is the distance of travel in kilometers that warrants breaking Sawm (Fast)? What if a traveler observes Sawm?
Answer: Some scholars maintain that one is allowed to shorten a a four-Rak`ah Salaah (Prayer consisting of four units) and break Sawm during the daytime in Ramadaan in any travel in the literal sense, i.e. whether the distance is long or short. However, the majority of scholars stipulate a distance of about 80 km… read more here.