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.
As wide as 4mm on a ruler
4mm its in the question
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.
There are 25.4mm to one (1) inch, so there would be approximately six (6) 4mm beads per inch. If buying a 16" hank of 4mm bicone beads, you would be buying approximately 100 4mm beads.