I think inches would only matter to a Transformer if they were making something, otherwise it would be too small for them to be any real use.
As for feet, it would depend. Some of the Transformers get their sizes fluctuated around in the comics and at least in G1 I think. In a sig pic on here of Thundercracker, Spike's father looks very tiny. But in another instance a snake dropped from a tree and was around somewhat on Starscreanm's neck and shoulders. And it must've been at most at least 30 ft. long, more or less, and Starscream is problably suppost to be the same size as Thundercracker. It wasn't big, but it wasn't tiny either. So feet would be bigger or smaller depending on the Transformer and what size it happened to be in the comics or cartoon. But I think ft. would be significant enough to them, unlike inches.
Hmmm...lets try a 50 ft. Transformer:
I am 5 ft., so every ft would be 10 ft.
Going by this measure a 5 ft. person would stand about 6 inhes tall, a 6 ft. person would probably be about 6 1/2 to 7 inches. If he was enclosed in a fist, he would stick out after the midline of his chest and at the bottom, past the mid-thigh.
The Transformer's head might be at least 6 1/2 to 7 ft. from chin to top of the skull, or on me, at least 7 inches.
From bottom of chin to groin, at least 20 ft, or two ft.
Bottom of groin to floor, 23 ft or 2 ft. 5 inches.
These measurements are probably not precise, but are close estimates instead. I used a ruler to guestimate, and I hope I got it close.