German phrase
Wie groß darf ~ sein?
Meaning
How large can ___ be
When to use it
It asks about allowed size. This polite question checks a formal size limit.
Example dialogue
Wie groß darf das Paket sein?
How large can the package be?
Es darf höchstens 1 Meter Kantenlänge haben und 30 Kilogramm wiegen.
It can have an edge length of up to 1 meter and weigh 30 kilograms.