* いくらですか (ikura desu ka) - This is the most general way to say "how much" and can be used for both goods and services.
* どれくらいですか (dore kurai desu ka) - This is also a general way to say "how much," but it is often used for quantities or measurements.
* 何円ですか (nan en desu ka) - This is specifically used for asking the price of something in Japanese Yen.
* 何個ですか (nan ko desu ka) - This is used to ask the quantity of something.
* 何時ですか (nan ji desu ka) - This is used to ask the time.
Examples
* このシャツはいくらですか (kono shatsu wa ikura desu ka) - How much is this shirt?
* この本の厚さはどれくらいですか (kono hon no atsusa wa dore kurai desu ka) - How thick is this book?
* このコーヒーは何円ですか (kono koohii wa nan en desu ka) - How much is this coffee?
* このケーキは何個ですか (kono keeiki wa nan ko desu ka) - How many pieces of cake are there?
* 今は何時ですか (ima wa nan ji desu ka) - What time is it now?