A man who repeatedly stabbed his wife to death while she pleaded with him to stop has been sentenced to at least 16 years in prison.

Fijian born Adi Cavora Baleimalea Boe Tavuki died at Narrabeen caravan park in Sydney's northern beaches in October 2012 after she was stabbed 22 times in the face, chest and abdomen by her husband, Ratu Serutawake.

The Supreme Court heard that while she was being attacked, the nursing assistant repeatedly said she was sorry and begged for him to stop.

But it was only when the handle of the knife broke off that he did.

In sentencing him on Friday, Acting Justice Jane Mathews said the murder was completely out of character for Serutawake, who now suffers from post-traumatic stress as a result of what he had done.

Serutawake told police he had killed his wife after an argument broke out between them early on October 21.

She had started throwing things and smashing things, had punched him and at one point threatened to leave.

After a second argument in which she smashed something else, Serutawake said he snapped.

"I didn't plan it that way ... we were supposed to celebrate her birthday today. I'm so sorry for what I've done," he told police that afternoon.

He had pleaded not guilty to murder on the basis of self-defence and provocation, but this was rejected by a jury who found him guilty in October this year.

Acting Justice Mathews said his response was "completely out of proportion" to his wife's actions.

"Far too many killings occur in a domestic setting such as this, and it is incumbent upon the courts to impose sentences which will hopefully operate to deter others from behaving in a similar way in the future."

She sentenced him to a minimum of 16 years and a maximum of 20. His earliest date of release is October 2028.