Why can I do up 28 inch Gap jeans but not 30 inch Levis?

[Trills]

Because they are all liars, obviously.

Bought off ebay to try the whole "bold curve" thing (otherwise known as sticky-out-bum).

Nope.

Gap are ridiculously over generous with their sizing!

I understand that a "size 10" is meaningless but it's a bloody measurement.

An inch is an inch is an inch.

(no jokes about men saying that "this much" is six inches please)

Measure your waist. Measure your jeans, there's your answer!

If the jeans sit on the hips rather than the waist, they should measure bigger obvs.

I wear a 28/29 in Gap and can fit into Levis Slim Fit and 501 CT in a 29/30 but couldn't get a Levi Bold or Demi Curve on in anything smaller than a 33!

I am a size 14-16 generally and can wear S or M in gap. My gap jeans are a 31. Their sizes are wonky.

My jeans don't actually go very near my waist...

Levis claim that a "size 30 or 31" is a size 12 in the UK

No actual measurements provided sadly.

Trills the link you have provided does give measurements

Measure the actual waistband - my DP measures 40 inch and wears 32 inch Hollister jeans.

Next jeans are enormous too. Their flattery sizes have gone mad. I wish everybody would standardise. We'd all get the shock of our lives to begin with but once we'd digested the brutal truths it'd be easier to shop right.

Imagine the main factor is where the waist sits, though that said I wear 29" Levis Demi-Curve and 29" Gap jeans.

I have some 90s 501 jeans 31' waist I can only just do up yet can fit into a gap 26' waist.

Jeffrey thanks for that - I had google and been taken straight to the "oh it's about a 12 y'know" vagueness instead of measurements.

I am worried now that the mobile site is giving different info to the main website...

On the main website it says that for women's bottoms, get a "size 30-31" if your waist measures 30 1/2 - 33 inches.
(mine does)

On your picture it says to get a size 30 if your waist measure 27 - 27 3/4 inches.
(mine certainly does not)

So clearly the jeans I bought obey your chart and not the chart I read!