I'll be installing a new wood laminate floor in the bathroom, 3/8''
thick. The old floor was carpeting/padding over vinyl stick-on squares.
Lovely to have around the toilet. My aim is not that good all the time.

The hallway has the same carpeting over padding, so the two rooms were
previously on the same level. Now I have a slight shift in height, and a
transition from one floor covering type to another, so I'm wondering
what I need along the lines of a threshold. I've left enough hallway
carpeting protruding into the bathroom so I can trim it back as needed
to fit under (or against ?) the threshold.

Before I start installing the new flooring I reckon I need some idea of
what's gonna happen there in the doorway. Is there a Thresholds 101 web
page someone can point me to?
--

Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westphalia: "Mellow Yellow (The Electrical Banana)"
KG6RCR

"Mike Rocket J. Squirrel Elliott"
et wrote:
I'll be installing a new wood laminate floor in the bathroom, 3/8''
thick. The old floor was carpeting/padding over vinyl stick-on squares.
Lovely to have around the toilet. My aim is not that good all the time.

The hallway has the same carpeting over padding, so the two rooms were
previously on the same level. Now I have a slight shift in height, and a
transition from one floor covering type to another, so I'm wondering
what I need along the lines of a threshold. I've left enough hallway
carpeting protruding into the bathroom so I can trim it back as needed
to fit under (or against ?) the threshold.

Before I start installing the new flooring I reckon I need some idea of
what's gonna happen there in the doorway. Is there a Thresholds 101 web
page someone can point me to?

Just get a piece of carpet reducer the same color / pattern as your laminate.
One edge overlaps your laminate, and the other edge butts up against the carpet.
Use a piece of tack strip salvaged from the bathroom tearout to anchor the
carpet along the reducer. The transition line (where the carpet butts against
the reducer) is usually centered under the door.