I'm embarrassed to ask this about scaling faces I'm not a smart guy. I haven't been able to google the answer or figure this out on my own.

I placed a cylinder down and scaled it by millimeters to 12.9 mm on x and y, but I also need to change the top end face size to 12.7 mm. I can't figure out how. Unlike the object properties, in edit mode the only property that seems to be available is something called Median. According to google, median just displaces the location of the centerpoint of selected stuff.

All I wanna do is scale a single face of this cylinder by exact millimeters, but so far this software doesn't seem to be capable of that. pressing S and typing anything in just gives wild results.

UPDATE - I gave up on it. I realized that blender isn't as powerful as I had hoped and just did a bunch of extremely time consuming boolean stuff to make 2 cylinder faces into 1 object to get the desired result.
Apparently the folks on the development team have been neglecting the smaller, more important features in favor of professional features that I'll probably never use in my life. No judgement here. It's their software, they can do whatever they want with it.
First make sure to start with a 1 base: scale the base cylinder to one in all dimensions.

If you've added a standard cylinder, it should be 2x2x2 meters.

So scale it 0.5 in object mode, then apply scale CtrlA to have the same in edit mode.

Once done enter edit mode, take the faces you need (maybe the bottom of the cylinder) and scale 12.9: S12.9

Now select the top part and scale 12.7: S12.7.

The proportions should be good. Now scale all 0.001 to have it in millimeters.



In the blend file above, top part is 12.7 and bottom part is 12.9.