The United Kingdom has 4 consituent parts: England, Wales, Scotland and the Republic of Northern Ireland.

England: 50000 mi² (129500 km²)

Wales: 8000 mi² (20700 km²)

Scotland: 30500 mi² (79000 km²)

Britain (England, Wales and Scotland): 88500 mi² (229000 km²)

UK (Britain and Northern Ireland): 95000 mi² (245000 km²)