It depends on the circumstances. A plea of guilty is a point in the accused's favour; not trying to lie a way out; being frank helps.There is no fixed penalty. The 'duty solicitor' at court can best advise, or any solicitor if he/she does criminal cases. It all depends on what the injuries were , whether the crime was premeditated, whether weapons were used, whether there was drink involved, what motive the accused had, whether there was real provocation as would affect a calm, normal individual, the character and record of the accused and much else.