There are several reasons to do your taxes using a computer program First is the reason I originally did mine on computer back in the 1990s. The computer will do all the calculations for you so you do not have to worry about making arithmetic mistakes. Several years I made either a $100 or $1000 arithmetic mistake, doing a subtraction. IRS corrected it and either increased my refund or notified me of amount I owed, but it was irritating. Second is if you are owed a refund doing the taxes on computer and electronically filing will make getting the refund quicker. Even if you do on the computer you can still print the tax forms and file by paper if you owe and make when the money comes out of your account later. Third the tax programs will help you in making sure every thing is filed. If you have used the same program several years it will compare this year against previous years and you can see if you forgot to claim a deduction or failed to include a earning like interest. Sometimes the program will also tell you that you may have overlooked a deduction or if you type a wrong figure in it may catch error, for instance typing wrong Medicare earnings may be caught when does not match Medicare taxes. Thanks Mary for the question