He was sentenced on Friday to 17 years and three months in jail with a non-parole period of 11 years, backdated to the time of his arrest.

He will be eligible for release in December 2031.

Supreme Court judge Richard Weinstein described Ratke's actions as "bizarre, senseless, strange and tragic".

The elderly man stabbed his wife at least 17 times as she lay in her bed after telling him she was planning on going shopping for Christmas presents the next day.

Ratke later told a forensic psychiatrist he thought of the upcoming Hungarian Christmas as “D-Day” as they would not be able to afford to pay for it.

Justice Weinstein noted some of Ms Ratke's wounds were defensive, indicating she was aware of being attacked by "the person she loved and trusted most".

Ratke initially told the police he had stabbed his wife just three times and appeared shocked at finding out the extent of her wounds, the court heard.

Justice Weinstein accepted the killer was likely suffering from a major depressive illness with narcissistic personality traits at the time of the murder.

Ratke sent a message on social media in which he admitted hurting his wife, prompting police to go to their home.

They found him unresponsive but breathing in the kitchen.

A note found nearby stated: "In all these yrs (sic) I’ve never done a selfish act always put my family 1st ... the first selfish act cost my wife dearly."

"With an IQ of 134 you would think that I could have been smarter & not made my wife pay 4 my stupidity," it said.

Ratke's lawyer argued his compromised mental health explained how he allowed their financial affairs to become so dire without seeking any help or "taking basic steps" to address the situation.

The couple's only child was a daughter who died from cancer over 20 years ago at the age of 21.

Ms Ratke was described by her niece in a victim impact statement as "a beautiful, kind, caring and loving aunt who was adored as a mother and godmother".

1800 RESPECT (1800 737 732)

Lifeline 13 11 14

beyondblue 1300 22 4636