The main path is 150 miles (240 km) long and stays close to Sussex's borders with Hampshire, Surrey and Kent, connecting Thorney Island (50°49′16″N 0°55′16″W / 50.821°N 0.921°W / 50.821; -0.921) to Rye (50°56′56″N 0°43′44″E / 50.949°N 0.729°E / 50.949; 0.729).

[4] To the west, Bede describes the boundary with the Kingdom of Wessex as being opposite the Isle of Wight,[5] and which later fell on the River Ems.

[2] The Sussex Border Path begins at Thorney Island, now effectively a peninsula that juts into Chichester Harbour.

[citation needed] The path forms a 9-mile (14 km) circuit around the island;[1] it then extends across the South Coast Plain to Emsworth on the Hampshire side of the River Ems, the river which forms the Sussex-Hampshire border at this location.

The Mid Sussex Link begins at East Grinstead and passes through Sharpthorne and Scaynes Hill to Ditchling, then over the South Downs to Fishersgate, between Southwick and Portslade.