Using the latest version of TextMesh and Unity 5.6, when changing font on editor to font size 18, shows up correct in editor, but when I build on iPhone the font has gone smaller?
Any issues reported similar to this?
Not sure what I’m doing wrong?
Do you have text auto sizing enabled on the text object? Since the screen size could be smaller than in the editor the point size would be reduced.
Outside of that, the point size should be the same.
Can you tell if it is using the same font which is just smaller or perhaps it is using a different font?
I have attached a screenshot, long story short, I only used TextMeshPro as Unity did not fix a huge performance bug with Text and Apple devices, where it would drain performance, till this day I’m not sure if they fixed it. TextMesh did not have this issue 
I upgraded from very old version and noticed the font had changed that comes with TextMesh, therefore some problems.
All in all see what you think below:
Let me know your thoughts, thank you…
I presume you are using the Canvas system since you are using the TextMeshProUGUI component as opposed to the normal TextMeshPro component. Correct?
If you are using the Canvas system, do you have some Canvas Scaler or something on there?
Can you see if you get the same behavior with a different font?
Just for fun, load example scene 1 and see if the text size appears to change as well in that scene?
Thanks dude, was a issue in the end with “AutoSize” I needed to enable this then fix up the text.
The font also seems to have changed new default from old version of asset.