Distance from London, United Kingdom to Barcelona, Spain. The total distance from London, United Kingdom to Barcelona, Spain is 707 miles. This is equivalent to 1 138 kilometers or 615 nautical miles. Your trip begins in London, United Kingdom. It ends in Barcelona, Spain. Your flight direction from London, United Kingdom to Barcelona, Spain is South (170 degrees from North). The distance calculator helps you figure out how far it is to fly from London, United Kingdom to Barcelona, Spain. It does this by computing the straight line flying distance (as the crow flies). It uses the great circle formula to compute the total travel mileage.