Ask HN: How much you increase your salary for a new job?

Hi all,

I am being interviewed for few jobs. That's a good thing however I am struggling every time to give a number when asked as I don't know how much I can ask mainly because I am not earning too much at my current job and also to be fair I am afraid to give my willing number.

I have already learned once you gave your current salary you cannot expect much increase.

So would be appreciated if you could give me some insights how you have dealt with kind of this situation.