Hello, I have bought an iPad Pro, but I don't know how many inches it is, the seller said it is 9/12, but it is smaller than my 9/12 iPad, which is a 2016 model.

Screen sizes are always measured diagonally between the screen corners - e.g. measuring diagonally between the upper-left and lower-right corner of the screen…

By example…:

2021/2022 iPad Pro 12.9”

20121/2022 iPad Pro 11”

You should also note that that the corners of the visible screen are slightly rounded. The diagonal screen measurement will be to a the corners of a “normalised” rectangle - this being slightly larger than the measurement between the rounded corners.

You can compare all the major specifications and physical dimensions of iPad models here:

iPad - Compare Models - Apple

Hello ~ If you are try to identify your iPad click link below for helping information…

Identify your iPad model - Apple Support

I hope this helps.

~Katana-San~