What if I can't pronounce the phrase correctly?

Show it written on your phone or point to it in a phrasebook. Most people will understand from context even if your pronunciation is rough. The word 'toilet' is also widely understood in many countries as a borrowed word.

Is it rude to ask for the bathroom immediately when entering a restaurant?

In most countries, no. It's a normal request. In Japan, you might want to say 'sumimasen' (excuse me) first. In very formal restaurants anywhere, ordering something small first is polite, but if it's urgent, just ask.

What if there's a language I didn't prepare for?

Use Google Translate's camera feature to translate signs in real-time, or type the phrase and show the translation. The word 'WC' (water closet) is understood almost everywhere. Pointing and looking confused also works universally.

Do I need to know different phrases for different types of bathrooms?

No. One phrase for 'Where is the bathroom?' works for all situations. You don't need separate phrases for public restrooms vs. restaurant bathrooms vs. hotel bathrooms.

Should I learn how to ask for the men's or women's room separately?

No. Ask where the bathroom is first. Once you find it, the pictograms are usually clear. If not, you can ask 'for women?' or 'for men?' while pointing, or look for the local words for men/women on the doors.

What's the difference between toilet, bathroom, restroom, and WC?

They all mean the same thing, but different countries prefer different terms. Americans say 'restroom' or 'bathroom'. British say 'toilet' or 'loo'. 'WC' (water closet) is universal signage. Use whatever the locals use, but they'll understand any of them.

How to Ask Where the Bathroom Is in Any Language

Knowing how to ask for the bathroom is the single most essential travel phrase. Learn the local phrase before you land, practice pronunciation, and carry a written version as backup. Most places also understand the universal sign of pointing down and looking confused.

Learn the phrase before you go. Look up how to say 'Where is the bathroom?' in your destination language. Write it phonetically. Practice saying it 10 times out loud. Record yourself and compare to native pronunciation on Forvo.com or Google Translate audio. Your accent doesn't need to be perfect — just clear enough to be understood.
Know the local vocabulary. Different countries use different words. In the UK, ask for the 'toilet' or 'loo', not the 'bathroom'. In France, it's 'les toilettes'. In Japan, 'toire' or 'o-tearai'. Americans say 'restroom' or 'bathroom'. Using the wrong term usually still works, but using the right one gets faster results.
Memorize the critical word. At minimum, memorize the word for 'toilet' in the local language. You can point and say that one word and someone will point you in the right direction. Write it on your phone's lock screen notes for the first day until it sticks.
Use gestures as backup. If the phrase fails, point downward, make eye contact, and look mildly urgent. This works everywhere. You can also show the written phrase on your phone. Keep a note in your phone that says 'Where is the bathroom?' in the local language and local script.
Recognize common signs. Learn to spot bathroom signs: WC (water closet — universal), pictograms of people, and the local words you've memorized. In Japan, look for トイレ (toire). In Korea, 화장실 (hwajangsil). In China, 洗手间 (xǐshǒujiān) or 厕所 (cèsuǒ). In Arabic countries, حمام. Take a photo of the local word when you first see it.
Know how to say 'emergency' if needed. For urgent situations, learn how to say 'urgent' or 'emergency' in the local language. Combining 'toilet' with 'emergency' and a distressed face will get people moving to help you immediately.

What if I can't pronounce the phrase correctly?: Show it written on your phone or point to it in a phrasebook. Most people will understand from context even if your pronunciation is rough. The word 'toilet' is also widely understood in many countries as a borrowed word.
Is it rude to ask for the bathroom immediately when entering a restaurant?: In most countries, no. It's a normal request. In Japan, you might want to say 'sumimasen' (excuse me) first. In very formal restaurants anywhere, ordering something small first is polite, but if it's urgent, just ask.
What if there's a language I didn't prepare for?: Use Google Translate's camera feature to translate signs in real-time, or type the phrase and show the translation. The word 'WC' (water closet) is understood almost everywhere. Pointing and looking confused also works universally.
Do I need to know different phrases for different types of bathrooms?: No. One phrase for 'Where is the bathroom?' works for all situations. You don't need separate phrases for public restrooms vs. restaurant bathrooms vs. hotel bathrooms.
Should I learn how to ask for the men's or women's room separately?: No. Ask where the bathroom is first. Once you find it, the pictograms are usually clear. If not, you can ask 'for women?' or 'for men?' while pointing, or look for the local words for men/women on the doors.
What's the difference between toilet, bathroom, restroom, and WC?: They all mean the same thing, but different countries prefer different terms. Americans say 'restroom' or 'bathroom'. British say 'toilet' or 'loo'. 'WC' (water closet) is universal signage. Use whatever the locals use, but they'll understand any of them.