Canada has the world’s longest coastline, according to widely cited national geographic measurements.
Canada’s coastline measures about 202,080 kilometres, including the shores of its mainland and many islands. It borders the Atlantic Ocean, Pacific Ocean, and Arctic Ocean, giving the country access to three major oceans. Canada also contains the world’s largest archipelago by area, the Canadian Arctic Archipelago, whose islands greatly extend the national shoreline.
Coastline totals are not perfectly universal because the measured length changes with map scale and the level of detail used. This is known as the coastline paradox: a more detailed measurement captures more bays, inlets, and irregular edges. Even with methodological differences, Canada is consistently listed as having the longest national coastline.
Russia, Indonesia, and Greenland also have very extensive coastlines, but their rankings depend on whether territories are included and how shorelines are measured. Canada’s coastline is especially complex because of its Arctic islands, Hudson Bay, large river mouths, and numerous Atlantic and Pacific inlets.