A Mildura man in his mid-50s held up a servo with a bent kitchen knife because he wanted to be jailed for "about 11 years" and then “retire in peace and not have people pester him”.

The plan hasn't worked out that well and despite being convicted and jailed, the would-be robber will probably be out in a month.

Michael Gregory Arthur Sinclair, 56, pleaded guilty to attempted armed robbery at a County Court sitting in Mildura on Monday.

The court heard about 6.15pm on December 15 last year Sinclair went to the Caltex service station in Red Cliffs, just south of Mildura, with a 22cm bent kitchen knife concealed in his back pocket.