I got some rims without any lug nuts and I was wondering how do u know what size lug nuts to use on the rims?

There are different ``types`` and ``sizes`` of lug nuts. Take one wheel into your local tire store and tell them what type vehicle they have to install on. They will show you the proper lug nut. If you get the right size but the wrong type, the nuts could work loose.

90% of lugnuts are "universal" and will work with all rims. If you are using a spacer or adapter, then you might need something different.

If they are nice shiney wheels that don't have a cover over the lugnuts, then you will want something nice and polished. If there is a plate to cover them, with a tiny screw to hold it in place, then you can use you stock ones.

Don't forget to get wheel locks! If you live or work near a ghetto, then you will need wheel locks. Go to any auto parts store or dealer and get a set of wheel locks. Your wheels can still be stolen, but why make it easy for them? Make them work for it.