Calm down is a widely used
Is Calm down rude?
To the person receiving those words, “calm down” the tone come across as condescending. Even if you try to sound very subdued and matter-of-fact. If you're the person saying “calm down” to someone who's visibly upset or distraught, you're subtly acting as if you have the upper hand.
How do you use calm down in a sentence?
(1) He just needs to calm down a wee bit. (2) Calm down for a minute and listen to me. (3) Calm down and think carefully. (4) Just calm down - shouting won't solve anything!