In the USA I’m chill indicates I’m good with that with whatever was mentioned) Other ways to say I’m chill: I’m good. I’m good with that. Cool. I’m cool. I’m in. I’m down with that. I’m down. It’s all good.

"I'm chill" usually means "I'm cool", "I'm calm", "I'm ok with that" It's informal and there's several ways of using it with slightly different nuances depending on context. Examples: If someone thinks I'm a little upset about something, I could reply "I'm chill". I'm replying, "I'm ok and I'm calm and not really bothered". Another use of the expression is if someone wants to know if I'm ok with something. eg. Person A: "You're ok with going to Peter's party ?" Me: "I'm chill" ie I'm ok with that. This is very informal and a language style a lot (most?) would never say. The style is a little restricted to a certain genre/class/group of people. That group may use it a lot, whereas others would never say it.

To "calm down" can also be said as to "chill out," but it's very casual and rarely used when speaking in formal settings (like work). Some examples would be: "He's a chill guy" (He's a calm and collected person). "Can you chill out please?" ("Can you calm down please?") "She has no chill" ("She's angry all of the time/she's an intense person"). Hope that helps :-)

To "calm down" can also be said as to "chill out," but it's very casual and rarely used when speaking in formal settings (like work). Some examples would be: "He's a chill guy" (He's a calm and collected person). "Can you chill out please?" ("Can you calm down please?") "She has no chill" ("She's angry all of the time/she's an intense person"). Hope that helps :-)

What a strange question.