16oz Ball Jars, I prefer the wide mouths, will fit perfectly in most cup holders. I've got it next o an Arizona Iced Tea can and it's only a little bit larger.

I just wasted a ton of time and energy measuring the circumference of each item and the ball jar is about 1" larger. The Arizona can was a rough 9.5" making the ball jar 10.5"

If you have an easier time visualizing diameters, that's 3.02" for the can and 3.34" for the jar.