Do I need to calculate tax owing on 3 months of self employment income or can I enter the total amount and Turbo Tax calculates that for me?

I retired in September 2017 and had 3 months of self employment income.  I am not a company. I entered the total amount I made in the self employment questionnaire but did not see where I would calculate what my taxes owing on that amount would be or where I calculate CPP owing on that amount.