That's going to depend on the brand. Normally it's about 1-2 inches in sizes so, for instance, the levi's website lists a 1 inch difference in the seat between sizes. In plus sizes, though, it's normally more like a 2 inch difference because they have to account for a wider range of body types. Now, in terms of pounds that's going to range like crazy because some times bodies lose weight and inches at the same time, sometimes weight hold still and inches come off and sometimes your body chooses to lose weight in certain areas and not others.
I think the most general rule of thumb is under 35 inches but that's completely absent from a relationship to height so I have to admit I'm pretty suspicious of that (a 35 inch waist is going to be very different on someone who is 5'0" and someone who is 6'0"). I've also heard half of your height (so at 5'7" that would mean 33.5"). That seems to make more sense to me at least as a cutoff between obese/overweight (and it actually corresponds well to my waist and weight too whereas I was under 35" for awhile now...). I've also heard that ideally women would be under 30 or 32 inches (I've seen both) so maybe 35" is more the difference between obese/overweight and 30/32 is the entry way into healthy. I'm just speculating here so I'm not 100% sure... Also, the hip-to-waist ratio should be under 0.8 and some even say 0.7...
Variance in inches
: Honestly, this could be a million things...
-when did you measure at both weights? where they at the same time per day? where you on your period? had you just eaten?
Just like when you weigh, your measurements change during the day and you get larger during your period so you have to be consistent about them.
-it could be an error in the measuring, maybe, maybe not
-are you using the same measuring tape?
-different bras=different measurements. I have some bras that put my bust size at 40" and others at 41"
-do you have kids? have you every nursed? my daughter has been weaned for over half a year but I still fill a fullness at times at night
-eat anything weird lately? or are you ovulating?
I've been bloated for about 3 weeks now and am about 1 inch bigger everywhere than normal but have actually lost weight.
I'm in the process of having a doctor run some tests but she said this is normal and probably related to digestional issues.