Measuring Hinges Corners 
Hinges can have square corners, or radius corners. If you're hinges have radius corners they're most likely 5/8" or 1/4" radius. To determine the radius hold a quarter or dime up the corner. If the quarter matches the radius you have 5/8" hinges, if the dime matches you have 1/4" hinges. Below is an example of a 5/8" radius hinge.
