The Tud's source is just south of East Dereham and it flows in an easterly direction for 27 kilometres (17 mi) to its confluence with the Wensum below Hellesdon mill.

According to a 2024 citizen science project,[1] the Tud should be classified as a chalk stream.

The Tud passes through the villages of North Tuddenham, Hockering, East Tuddenham, Honingham, Easton, Costessey and finally flows under the Marriott's Way before joining the Wensum at Hellesdon Mill.

The Tud's water is crystal clear, shallow, fast-flowing and has lush weed beds full of aquatic life including crayfish, lampreys, bullheads, freshwater shrimps and stone loach.

[citation needed] The river is well known for the quality dace fishing.