The absolute, largest unit of measurement is a Yottaparsec. 1 Yottaparsec is 3.08 x 10^40 metres! or 30,800,000,000,000,000,000,000,000,000,000,000,000,000 metres. Approximately 31 Duodecillion Metres
Well...im not too sure,but i think its a 1000.We do know for one thing,though,a yottaparsec=3.08x10^40m!That's insanely huge!!!It's something like this...30,800,000,000,000,000,000,000,000,000,000,000,000,000m
Contrary to popular belief, a light year is not the "longest unit". A parsec is. Or more specifically, a yottaparsec. The length of a parsec is found by constructing a hypothetical right triangle where corner A is the sun and has an angle of 90 degrees, and corner B is the earth (the assumed distance between the two is one AU, the average distance between them, approximately equal to149,597,870.7 kilometres¹), and corner C has an angle of 1 second of arc (1/3600 of one degree). A parsec, then, is the distance between A and C, approximately equal to 3.26 light years². The prefix "yotta" is the largest unit prefix of the SI denoting a factor 10^24 (a septillion, or 1000000000000000000000000) A yottaparsec therefore is a septillion parsecs, or 3.26 septillion light years, and is a distance far, far longer than the universe itself.
It is Meter , M