How can you test the percentage of tint on your car windows yourself?

Answer 1

you cant..but heres the tint percents:

6%--Limo..you cant see in from the outside
13% Dark: you can barely see in from outside
22% med-dark: seeing in becomes easier from outside
32% med-light: you can see in..but theres light tint thats visibily seen
50% light: you can clearly see in..but theres light tint..usually factorys use 50% on rear windows
70% is clear

Answer 2

Pull up next to a cop. Quickest way to find out that I ever heard of.