Grant Broster, 56, from Guildford, was on his family's kayak on 28 March when it capsized in front of his son.
Police said an extensive search of a wide section of the river had taken place over a number of days but Mr Broster had not been found.
Ch Insp Dave Mason said a decision had been taken to end the search.
He said information from the agencies involved in the search effort and detailed options had been exhausted.
"This was obviously a very difficult decision and one which we have not taken lightly," he said.
He added that search teams had done everything possible to find Mr Broster, using helicopters, drones, sonar, dogs and divers.
Mr Broster's family have been raising funds for the volunteers who carried out the search and have so far raised Â£5,623.
The search for a man missing since his kayak overturned on the River Wey in Guildford has ended, Surrey Police have said.