چقدر

Ask an amount. چقدر آب داری؟ asks “How much water do you have?” چقدر وقت داریم؟ asks how much time is available. Neither requires the questioner to specify a counting unit first.

Ask a price. In a shop, این کتاب چقدر است؟ commonly asks “How much is this book?” The everyday form این کتاب چقدره؟ uses the spoken copula. Outside a price context, give enough information to make the intended question clear.

Ask a degree. این اتاق چقدر بزرگ است؟ asks “How big is this room?” چقدر modifies the degree of the adjective rather than counting rooms.

Compare چند کتاب داری؟, which asks for the number of books. You can also ask چند ساعت؟ when you want a count in hours, while چقدر وقت؟ asks a time amount more generally. The intended question guides the choice.

چقدر also occurs in exclamations, where it expresses strong degree rather than requesting an answer. Use punctuation and context to distinguish those readings.