Single Breasted Tuxedo
A single breasted tuxedo (as shown above), just like a suit, will have the suit buttoned-up right in the front. This type of tuxedo is usually worn unbuttoned (which means that it will look less bulky – good for men with a larger frame). If you are going to wear your tuxedo unbuttoned, you should try to wear a vest underneath. The nice thing about the single breasted tuxedo is that it can also be worn buttoned up (depending on your own taste).
Double Breasted Tuxedo
A double breasted tuxedo will have a flap come over so that it is buttoned on the right side ( remember the picture’s left is your right – you probably knew this, but just in case).
This type of tux will make you look like you have a bigger frame and so it is a great choice for men with smaller frames. If you are wearing a double breasted tux, make sure to button up (this is mandatory).