[RedDevil]

If the threads at the front of both tires are closer together than at the back you have toe in, the other way round toe out.

Take a tape measure and an accomplice and make him/her put the tab in the outermost (easiest to reach) groove in the thread at the front of a tire.
If your tires have a straight groove, like in the middle of the thread as some tires do, take that.
Pull the tape measure tight and straight to the front of the tire on the other side and read what it says at your favorite groove.

Do the same at the back of each tire. If the distance there differs you don't have neutral alignment.

Divide the difference by the distance between front and rear measuring point and you get your percentage.

If at the front the grooves are say 1451 mm (57 1/8") apart
and at the back they are just 1445 (56 7/8"), so 6 mm (1/4 ") difference,
and the difference between both points is 305 mm (12"),
then you'd have about 2% total difference, making 1% toe out per wheel.