The Singapore area comprises mainland and other islands. The mainland of Singapore measures 50 kilometres (31 mi) from east to west and 26 kilometres (16 mi) from north to south with 193 kilometres (120 mi) of coastline. These figures are based on 2.515 metres (8 ft 3.0 in) High Water Mark cadastral survey boundaries.
Singapore is separated from Indonesia by the Singapore Strait and from Malaysia by the Straits of Johor.