I couldn’t find the exact pixel dimensions for this calculator, so I just measured it myself.
1 Centimeter = 22 Pixels, exactly.
Edit: It might not appear in the photo to be an exact alignment with centimeters, but that’s all because of the ruler sitting a little higher than the screen and the camera optical focus and crap.
Indeed, it’s exactly 22px/cm
I had to triple check for myself before being sure. But yep, when using my eyes straight on perpendicular (and not having to hold the camera with one hand), everything lines up precisely to 22px/cm.