Here in the United States: 1. If you are in a restaurant, movie theater, department store, etc., it is probably more common to say, "Excuse me. Where is the RESTROOM?" 2. If you are visiting someone's home, you should say "Excuse me. May I use the BATHROOM?" 3. Do NOT say "Where is the toilet?" Here in the United States, the use of that word is considered vulgar. That is, cultured people do not say that. (We only use that word if we need to call a plumber to fix the large bowl that people use to ...)

They're really all the same thing but different terms used in different countries.

I expect you'll get a variety of answers to this question! Washroom and bathroom refers to the same place (the room that contains the toilet). In my experience "washroom" is used more in Canada, and "bathroom" is used very commonly in the United States.

They are pretty much the same. But usually a washroom is a bathroom in a public facility. (restaurant, etc.) It is used in a very proper house. Ex: Would you like to clean up in the washroom? - usually talking to a guest. A bathroom always usually has a sink, toilet, shower/bath/or both (some bathrooms showers or baths. usually the ones in a public place, except at rv/camper sites.) Usually when you say,"I need to use the bathroom/restroom", you are saying that you have to go pee. >IMZ is right about different uses in different English speaking countries.

Check this site: http://www.rankopedia.com/Favourite-Slang-Word-For-A-Toilet/Step1/14268/.htm