The journey between King's Cross and Marble Arch in central London spans approximately 2.6 miles (4.2 km) by road.
By Tube, it's a quick ride on the Circle, Hammersmith & City, or Metropolitan lines from King's Cross St. Pancras to Paddington, then a short walk or one stop to Marble Arch—about 15–20 minutes total. Walking takes roughly 50–60 minutes through Bloomsbury and Marylebone.