Starvation mode?

So... how low does your metabolism actually drop when you're in "starvation mode"?
Anyone, anyone?
They say it "drops drastically", I just wanna know how drastically.
(And no, I'm not encouraging going into "starvation mode", before anyone attacks me with promoting eating disordered behavior. I'm just curious )

I think it depends on how many cals you eat.
Like if you only eat 600 calories a day, your metabolism will slow down to get used to those 600 calories. Same if you were to eat only 400 or 1000, etc.

I'd like to know how long it takes to get out of starvation mode?!?! Anyone have an idea, or an article to refer to?

Metabolism is the creation and destruction of energy; when you're not getting enough energy your body doesn't destruct as much. It doesn't function at an "optimism" which leads to the effects of tiredness, fatigue, poor circulation and coldness, hair loss, etcetc...

It's like your body shutting of sort of functions, so it doesn't use as much energy.