Double Bass Upright Bass

[jimvaughn11]

How can I determine if my upright is 3/4 or 7/8 bass, and , how to measure strings?
I measured about 48" on mine but see many stats on Talk Bass are 41"-43"

 

[LouisF]

In the attached, the String Length is th distance from the nut (at the base of the scroll/headstock) to the bridge. On this case 105 cm or @ 41 1/3".

Distinctions between 3/4 and 7/8 are often subjective but a 7/8 bass would generally have at least a 43-44" body length, 20" upper bout, 8-9" rib depth and a string length of 42 inches but that is VERY general.