First post…I should be working, but having asked this question a lot myself and searching the various threads here, I’m struck by the fact that this comes up so often and really not enough clear, univocal advice. A common rule is by invoking some claim about jacket length relative to the position of your hands (thumbs, curling your fingers, etc.). As a first assessment of jacket length, this rule seems to me a bad one since, as often pointed out, arm length is different, so the position of your hand, with arm hanging down, relative to the rest of your body will differ from person to person. So, as a general rule, “at your first thumb knuckle” isn’t one you should go by if you haven’t figured out proper jacket length on your body. I wish people would stop repeating this. It confused me for a long time. Indeed, too many members invoke this when answering the “jacket too long” question in threads, which I suspect continues to generate confusion since the rule is so body-relative. This probably prolongs continued threads about this. I often look at pictures where a member simply comments with “an inch too short/long” where I can’t see it, especially when one doesn’t even have a whole body shot! I suspect they are applying a relative to hand rule indiscriminately across the board. “Cover your ass” is the most commonly heard rule, which leads to the question, how much? Several members have posted what seems to me the best rule: The Right Rule: cover your ass while giving the longest possible leg-line. OK, the name is provocative! This seems to me where everyone assessing jacket length for the first time should start. It gives the “lower bound” on length of the jacket (sorry, I’m really an academic”). It seems the most general rule that accommodates different body proportions, while achieving an aesthetically pleasing, classic look. Of course, this leads one to wonder where one’s ass really ends (I’ve seen this question too), but it seems to me a simple guideline might just so long as length is not above than your crotch, just where the inseams meet. Does that sound right? Of course, you can then use your hands as a good reference point for your own body proportions. Just don’t promote the same rule for someone of a different body type! One “academic question”: is there a conflict between the “right” rule and one that invokes the midway point from shoulder to the floor, e.g. Flusser’s? This does lead to a question for discussion: how much leeway is there once you’ve found your correct jacket length? For example, can you let your sport coats go an inch shorter (as some have suggested)? Once we’ve set the rules, it would be a good discussion to see how much one can play with it. I invite forum members to post well-lit, full-length shots, front and back, of themselves or others to discuss jacket length. Namely, (a) does the subject adhere to the right rule above and (b) does any deviation seem ok, given other considerations (e.g. maybe you have very short arms, and thus, maybe a slightly shorter jacket would work). The best pictures would not be from high up, but probably straight on at the midline, so no angle distortion. Two sample posts on the nice tailor’s thread: Emptym http://www.styleforum.net/t/265924/...dback-and-alteration-suggestions#post_4815508 whose length looks just right by the above rule (pictures are nicely lit and at the right angle) and Acecow http://www.styleforum.net/t/265924/...ck-and-alteration-suggestions/15#post_4821631 A Tailor comments that the jacket is short, which is consistent using the right rule. I wouldn’t have thought it was drastically short compared to jackets one’s sees nowadays. Nor do I think it looks bad at all. So maybe within the leeway of playing with the right rule?