Do u know how to calm others down?

What method you use will depend on what is agitating the other person - extreme anxiety, neurosis, hysteria etc. Usually, calm talking cools them down except in hysteria where shock treatment works better, as a sudden tight slap..

I think laughter always helps. Looking at things in a humerous perspective always helps because it can show how sometimes we are taking a problem too seriously. However remember too that humor can be overdone if used too much.

by shutting up

no seriously when people are mad i dont say a dang word.

what am i gonna do? say "calm down" then they will beat the crap out of me haha lol jk

I'm assuming you don't mean through physical means like peppar spray.

If their angry, let them vent, just stay nearby to listen to their rantings while they beat up your punching bag or something.

If their sad, hold their hand while listening.

If their happy, ask them to take it down a notch.

If you listen to them calmly and let them know you understand what they are upset about (or ask questions until you do) they tend to run out of steam eventually.