Shh! Don't say "toilet"! (potential for gross-out, but please don't go there)

[Yvaine]

Oh, I also say baņo.

[Venus193]

IME, in NY most people say "bathroom" in a home and "restroom" or "ladies room" (or "men's room") in a business, although "bathroom" wouldn't be unusual even in a business.
But I think most people would totally understand and not really blink an eye at "washroom", "powder room","the head", or "the john". "The john" is usually said by men, and usually in bars (or by men who frequent bars).

"Toilet" would be weird to hear, as would "water closet" which I've heard is used in parts of Europe (and certainly I recall seeing doors labelled "WC" which were in fact restrooms). In fact "water closet" or "WC" might legitimately not be understood at all, same with "loo".  And as far as "loo" I think if someone without an accent said it here, many people would internally think "[eyeroll] geez a bit too much BBC America?"

Personally I can't stand the word "potty" often used by people when speaking to children or (IMO) when condescending to adults.

That also reflects my experience in NYC and I completely agree with the bolded.

[WillyNilly]

Lived in California all my life.

In a business I'd as for the ladies room or restroom. In a home it's a bathroom. A water closet refers to a bathroom that has only a toilet and sink, usually in the most public part of the house, though I'd never ask for the "water closet" because not everyone has one. The toilet is the actual fixture you eliminate in.

  It has always been my understanding that is what a "powder room" is as well - just a toilet & sink, often near the living room or right off an entrance to the home.  And I tend to never use the phrase "powder room" for the same reason - most people I  know don't have one.

[Tilt Fairy]

Agree with the other Brits on here. We call it the toilet or the loo.

[Margo]

In the UK, asking for the bathroom would make people wonder why you needed a bath.

The most usual word is probably "loo", whether at someone's home or in a restaurant, etc.  Using the word "toilet" isn't as common as it was. In public situations--  eg pubs, restaurants, shopping centres, halls -- you'd be most likely to ask "Where are the loos?" or possible "Where is the Ladies/Gents?" I don't think the words restroom or powder room are much in use.

I agree.

There is also "the little girls' room".

I disagree a littler. I agree that 'toilet' or 'loo' are the most common but asking for the bathroom is very common and readily understood. I think if you were visiting someone's home and wanted to go "May I use your bathroom" or "where's the loo, please" would be equally normal and equally well understood.

In shops/restaurants etc I think most people would ask for the ladies or gents, or for the toilets.

WC is readily understood but I think is less and less common, especially in speech  (you still see it on doors, sometimes)

Things like little girls/little boys room sound would be readily understood but come across as a bit twee.

I think most people would know what you were asking for is you said 'powder room' or 'rest room' but these terms aren't common terms - in the absence of evidence to the contrary I'd assume someone using those terms was a visiting American :-)

casual terminology include 'the bog' or 'the bogs' (or, most specifically, 'the [school] bog') 'the smallest room' or 'the khazi' (that last I think started as army slang - my grandfather, who served in WWII used to use it, and I think it's usually older people who would use that term)

(I'm a Brit in her 30s)

[Yvaine]

Oh, on the silly slang front, my dad would always say "I'll be in my office." In one place I lived, we'd say we were going to go study architecture, because there was a big encyclopedic book about architecture in the house that somehow became the typical "bathroom reading" (I think probably because it was easily read in small snippets).

[Margo]

'The Throne Room' is another...

[Tilt Fairy]

In the UK, asking for the bathroom would make people wonder why you needed a bath.

The most usual word is probably "loo", whether at someone's home or in a restaurant, etc.  Using the word "toilet" isn't as common as it was. In public situations--  eg pubs, restaurants, shopping centres, halls -- you'd be most likely to ask "Where are the loos?" or possible "Where is the Ladies/Gents?" I don't think the words restroom or powder room are much in use.

I agree.

There is also "the little girls' room".

I disagree a littler. I agree that 'toilet' or 'loo' are the most common but asking for the bathroom is very common and readily understood. I think if you were visiting someone's home and wanted to go "May I use your bathroom" or "where's the loo, please" would be equally normal and equally well understood.

In shops/restaurants etc I think most people would ask for the ladies or gents, or for the toilets.

WC is readily understood but I think is less and less common, especially in speech  (you still see it on doors, sometimes)

Things like little girls/little boys room sound would be readily understood but come across as a bit twee.

I think most people would know what you were asking for is you said 'powder room' or 'rest room' but these terms aren't common terms - in the absence of evidence to the contrary I'd assume someone using those terms was a visiting American :-)

casual terminology include 'the bog' or 'the bogs' (or, most specifically, 'the [school] bog') 'the smallest room' or 'the khazi' (that last I think started as army slang - my grandfather, who served in WWII used to use it, and I think it's usually older people who would use that term)

(I'm a Brit in her 30s)

Yep. All of this. Whilst the majority would say toilet or loo, nobody would blink an eyelid if you said bathroom. I prefer to use bathroom myself but it's interchangeable with toilet and loo here which are both words a bog-standard (no pun intended!) British person would use without hesitation.

As Margo said, powder room, rest room and (perhaps) WC would all be understood perfectly what you meant but would be unusual and infrequent to hear and maybe slightly amusing. It would also most likely give you away as either being from overseas or very very upper class (and even then, I think toilet or at least definitely bathroom is still the most commonly used phrased by our poshest classes). I've heard that members of the Royal Family use the word toilet. It probably sounds very unrefined to those from other countries but it's what everyone uses! I guess it comes from the olden days when you used to wash or groom and this was called "to toilet".

[EllenS]

Yes, I think the aversion in some parts of the US to the term "toilet" is due to the fact that over here it is used to designate the equipment, rather than the room. 

As a further point of regional interest, my mom used to sometimes refer to the equipment itself as "the commode" or, "the pot".  My paternal grandmother also used the word "commode". 

[Hmmmmm]

Lived in California all my life.

In a business I'd as for the ladies room or restroom. In a home it's a bathroom. A water closet refers to a bathroom that has only a toilet and sink, usually in the most public part of the house, though I'd never ask for the "water closet" because not everyone has one. The toilet is the actual fixture you eliminate in.

  It has always been my understanding that is what a "powder room" is as well - just a toilet & sink, often near the living room or right off an entrance to the home.  And I tend to never use the phrase "powder room" for the same reason - most people I  know don't have one.

The only time I see or hear that term these days is either on a new home house plans or occasionally an older aunt will refer to the powder room. I do have a friend I can hear telling guests "the powder room is down the hall" so I think she uses it.

[Awestruck Shmuck]

Born and raised in Sydney, Australia - of English parents.

Toilet, Torlet,'the ladies', Lav, Bog and Bathroom are the most common in my experience. Like other posters, I cringe when adults use the word potty - unless they are addressing a child under 5.

I tend to ask for 'the ladies' when out in public. In a private home I will ask for directions to the lav or the bathroom.

[Nikko-chan]

I call it the bathroom, or when out in a restaurant, the ladies room. When I was a child all of the kids at school were taught to say lav (lavatory).

I am a 24 year old female in Ohio in the U.S.

[katycoo]

Toilet, Torlet,'the ladies', Lav, Bog and Bathroom are the most common in my experience. Like other posters, I cringe when adults use the word potty - unless they are addressing a child under 5.

Fellow Aussie.

You know, lav, bog and dunny are all terms I'd clearly understand, but I couldn't tell you the last time I heard one used in a manner not entirely facetious.

[Outdoor Girl]

Canadian, grew up small town, live in the city for the last 25 or so years.

In public, washroom or restroom.  At home, the 2 piece is the washroom, the 3 piece is the bathroom.  When I'm out at friends, it's the washroom, the can, the loo, the facilities.

A friend was working a receptionist type position.  If she left her desk, someone had to cover for her.  So she'd say to one of her coworkers, 'Can you watch the desk for a minute?  I've got to go check my hair.'  I liked that one so I started using it.

[Bluenomi]

Toilet, Torlet,'the ladies', Lav, Bog and Bathroom are the most common in my experience. Like other posters, I cringe when adults use the word potty - unless they are addressing a child under 5.

Fellow Aussie.

You know, lav, bog and dunny are all terms I'd clearly understand, but I couldn't tell you the last time I heard one used in a manner not entirely facetious.

Another Aussie and I agree. Loo, toilet, bathroom are common though.