Well if you are asking the exact meaning of Bathroom then it is "स्नानगृह" (pronounced as ES-NAN-GRAH) however generally in regular day to day life we never say this we always say "Bathroom kahan hai"... Its just because English is now so mixed with Hindi that even in day-to-day life we speaks many English words as it is is in Hindi... so formal way to ask "Where is the bathroom?" is "Bathroom kahan hai".

I just saw your comment. So Bathroom the elder brother of toilet I guess shares the same fate like toilet. In hindi there are three words for Bathroom गुसलखाना (m) स्नान-घर (m) स्नानगृह But again more frequently used is Bathroom. eg if u wanna say Your bathroom is big - Tumhara BATHROOM bada hai. rather than saying tumhara Gusalkhana bahut bada hai. * I have heard people say Gusalkhna or Snangrah but 90% of the times ppl say Bathroom kahan hai? = Where's the Bathroom. * You know the thing is that english words like Bathroom, toilet etc have become an inseparable part of our daily speech that even those who don't know english know these words. in fact Hindi in it's purest form is not spoken in day to day businesses. It's a blend we use. you must have noticed that. so even if you ask an illiterate person "Bathroom kidhar hai?" he or she can guide you.

शौचालय (Toilet)... Well as for me I have not heard many say "Mujhey शौचालय jana hai" - I need to go to toilet. Ppl say Mujhey toilet jana hai - I need to go to toilet. or शौचालय kahan / kidhar hai ? - Where's the toilet? In colloquial Hindi ppl say Toilet kidhar hai? = Where's the toilet. (The reason could be pretty heavy word to say can make u breathless SHAUCHALYA and long too so may be by the time you finish saying SHAUCHALYA KAHAN HAI the weather in your pants changes :p :D... Hey don't count as my answer that's just for smiles :) ) So most ppl say Toilet. But that doesn't mean Shauchalya is not used. You hear and see shauchalya written at public places like Railway station Announcements and Advertisments made in pure hindi use Shauchalya. So it a pretty useful word to know and be read sometimes at some places The toilet word is not written but Shauchalya only. The last time I heard this I heard this word was in a plane. Like they make the announcement before landing that we are going to land the passengers are requested not to use the toilets. First they make in English then the same in Hindi and it's something like this yeh vimaan kuch hi palon mein so and so airport par land karne jaa raha hai. Sabhi yaatriyon se nivedan hai ki landing ke samay SHAUCHALYA ka pyayog na kare. Dhanywad Now this is Pure Hindi it says This plane is going to land at so and so airpot in a few moments. All passengers are requested not to use the toilet during this period. Thank You. Ting Tong :D So the gist is शौचालय is a useful word to know but not very frequently used in collloquial speach more common is it's English counter part toilet. atleast in cities. Hope it helps still any question you can always ask :) P.S Just as I was typing my bro passed and saw me typing and laughed and says "Shauchalya! I never say that I just say toilet!" :D so u know what I mean by collloquial Hindi :)

So how do I ask "Where is the bathroom?" say I'm in some place or house or anywhere... Is this word proper to use?

there is a vartani ashuddhi (spelling mistake) it is शौचालय, and it means toilet, not place where u take bath