French phrase
Je serai en retard d'environ ~.
Meaning
I'll be about ___ late.
When to use it
A polite way to report a delayed arrival. It gives an approximate delay in advance and sounds calm and considerate.
Example dialogue
Je serai en retard d'environ dix minutes.
I'll be about ten minutes late.
D'accord, je t'attends.
Okay, I'll wait for you.