Tony McCluskie was found guilty of murder by an 11-one majority. He had admitted manslaughter.
Ms McCluskie's mutilated body was found floating in the Regent's Canal in east London.
Gruesome details emerged at the Old Bailey in scenes which could have come from the BBC soap.
McCluskie, 36, a window cleaner and skunk cannabis smoker, claimed to have lost control after a tirade of abuse from his sister.
He said the last thing he remembered was her coming at him with a knife.
But the prosecution said he killed his 29-year-old sister after she lost patience with him and asked him to leave the flat in Shoreditch, east London, where they lived. The final straw came when McCluskie left taps running and a sink overflowed in March last year.
She was killed by being hit over the head at least twice and her body was hacked into six pieces using a cleaver and a knife.
The next day, McCluskie carried a suitcase to a local cab firm and was last seen taking it towards the canal.
Ms McCluskie's torso was found a week later when the case snapped open, and her limbs were found in black bags a week later. But her head was not found for six months before it was discovered in the water.
Ms McCluskie who played Kerry Skinner on screen in 2001, was immediately missed. McCluskie joined friends who launched extensive searches across east London to find her.
Former EastEnders co-stars Natalie Cassidy and Brooke Kinsella appealed on Twitter for help.