What is the difference of meaning between "a bigger size" and "a size bigger"?

I read the two forms. I learned that the adjective is before the noun but I guess that there are some exceptions. Is there a difference in meaning?

Solution 1:

In "a size bigger", "size" is used as a unit of measurement.

This usage presumes that whatever is being discussed (clothing, drink servings, etc.) comes in a discrete set of possible sizes. Thus, for example, if a café serves coffee in "small", "medium", "large" and "extra-large" cups, then a medium coffee would be "a size bigger" than a small coffee (and a large coffee would be two sizes bigger than a small, and an extra-large would be three sizes bigger than a small).

Compare this with other similar unit-based comparisons, like "He's an inch taller than her" or "This road is a mile longer than the other one" or "This ladder is two steps taller than that one."

On the other hand, "a bigger size" simply refers to any size that is bigger than the one it's compared to. So, in the same café example as above, "medium", "large" and "extra-large" would all be bigger sizes than "small".

Solution 2:

"a size bigger" means the next size. More like a unit and discrete. "a bigger size" means any other size as long is bigger. Continuous and unlimited.

"That building is a brick taller. That's why this building needs a taller brick"

Solution 3:

"A size bigger" is more specific than "A bigger size". If a lady tries on a size 12 dress and finds that it is just a bit too small she might ask an assistant for one "A size bigger", in which case she should be offered the same dress in a size 14 (in the US and UK there are no odd-numbered sizes). If the size 12 was much too small she might ask for one in "A bigger size" in which case the assistant should offer offer a size 14, 16, 18 or even bigger.