Okay I don't want to be rude, but that's a pretty...well how can I put it? It's just a question most people would know the answer to off the top of their head. But it's not for me to judge you so here we go: The answer is...(drumroll)...4mm! By the way I am assuming you mean 4 millimetres and 8 millimetres.
4mm is smaller than 5mm
1.8 mm is smaller than 8mm. 8mm is 4.44 times 1.8.
Smaller 3cm = 30mm so 8mm is 22mm smaller than 30mm or 3cm
The urethra is bigger. Ureters average 3-4mm in diameter, while urethras average 6-8mm.
A 4mm diamond measures 4mm in at least one measurement.
Mount Everest is not getting smaller. Every year the mountain grows about 4mm as a result of the upward thrust generated by two opposing tectonic plates.
4mm its in the question
As wide as 4mm on a ruler
4mm is 0.15748032 of an inch.
4mm-6mm in inches = -2
Not sure what your working on but it might be 3/8" and not metric.
8mm tapes can only be viewed with the aid of an 8mm player. One's best bet to watch 8mm tapes in this case is to purchase another 8mm player that is not broken.