Just curious if there is a standardised method of measuring tread width as in which part exactly is tread width measured from?

 

Yeah, after a hard day of driving, measure from the outer "chicken strip" inward and there is your usable tread width

But seriously, just measure from the furthest outer portion of where there is signs of road contact. You are already doing this to gauge your alignment and air pressure settings, I guess you could measure the tires if you wanted to as well. As far as a "standardized" form of measurement, I couldn't tell you. Its probably different from manufacturer to manufacture, so this just gets back to measuring what you have.

 

what about measuring tread depth?

 

There is not standard way to measure. That is why some tire manufacturers do not list tread width. Tread depth is easy. Just measure in the groove to the bottom of the groove. The wear bar indicator is at 2/32".

 

Tread depth gauge but don't know about width.

 

Would u consider a reasonable way would be measuring from triangle marker tip to tip?

 

No because those are placed in different relation to the actual tread/sidewall depending on the tire. I have found on most tires they are too far down on the sidewall to be used as such. They are simply to point out where the wear bars in the tread are located.