Andrew McKinlay, 39, admitted murdering mother-of-three Josephine Steele, in her home in Dobbies Loan, Glasgow, on October 9 or 10 last year, when he appeared at the High Court in Glasgow last month.
The court heard that after the five days, McKinlay bought air freshener and bleach to cover the smell, before moving to a friend's flat. The body of the 39-year old woman was not found until October 30, when she was reported missing after failing to attend a medical appointment.
McKinlay appeared for sentencing yesterday at the High Court in Edinburgh.
Defence counsel Thomas Ross told judge Kenneth Maciver that Ms Steele "had been very kind" to his client.
"He cannot believe it himself, what he did."
The judge said: "This was a brutal killing. There were five penetrative stab wounds, several other cuts and evidence of defensive wounds."
Members of Ms Steele's family said after they were too distressed to comment.