The size of stud earrings for men is determined by the carat weight. Keep in mind that this refers to the weight of the stone and not the size of the gemstone itself.
The most common carat weight for men’s diamond studs is between 0.25 and 1 carat. But if you want to make a bold statement, you can go up to 1.25 carat or heavier (as long as it’s what you want and you enjoy wearing it).
An earring’s cut or setting can also impact the look of your stud. When it comes to round stud earrings for men, a solitaire is timeless. This refers to a stud set with a single diamond, using a prong-style setting will maximise its brilliance. A halo cut, meanwhile, surrounds a bigger diamond with smaller diamonds to create a halo-like effect
The ideal size for a men’s diamond earring stud, though, is really what you enjoy wearing.