"Hvad er længden af jeres rejse?"

Translation: What is the length of your journey?

[chaered]

Does this refer to the duration or the distance covered?

[Frederikbr]

Can be both. But it does seem like a little unnatural question to ask. Would be more normal to ask (keeping 'jeres rejse' as the subject): "Hvor lang tid varer jeres rejse?" (duration), or "hvad er afstanden af jeres rejse?" (distance)

[Mingan8]

Are those sentences common? In English, I'd ask directly How long is your journey? Is there a Danish equivalent and how common would that be?

[LucBE]

"Hvor lange er din rejse?" ?

[VivianVeile]

Hvor lang er din rejse

[KatKlover]

This is an unnatural question. "Længde" is used strictly for physical measurements, but would not be used for periods of time, nor long distances. "Afstand" would not be used here either, as it refers only to a short distance, such as if you are standing a distance away from someone or some thing.

*I am a fluent Danish speaker, who lived in Denmark for 9 years.

[J.T.307693]

How would you formulate the question instead?

[VivianVeile]

Hvor lang er jeres rejse (distance) or: hvor længe skal I rejse (time)

[HastaLaVista83]

ordnet.dk actually says that "længde" can also be used to describe the duration of something (point 2).

https://ordnet.dk/ddo_en/dict?query=l%C3%A6ngde

[chaered]

Tak for svaret!

[ycUvuSap]

Er udtalelsen rigtigt? Jeg hører "længden med jeres rejse" or something like that.