Metal Bending Guides
For those that are Do It Yourself type and want to know a quick and easy way to measure bends into your measurements for your sheet metal parts, see the below basic bending guides.
This is a great online calculator to use for all the measurements needed talked about in the above guides.
For those that are super technical in to things, look into the below link for great information.
The below Guide 2, is an example if you took inside measurements and need to know where to bend to retain the inside measurements. Also if you have more than one bend in the piece you are making.