It means, "how much do you have remaining?"
If you're waiting on someone to do something, you may ask them this to get an idea of how much longer it will take for them to complete their work.
In the Southern United States, the word "like" will be used in place of "lack"; see: "How much you like?"
John: I can't come over until I've finished painting my fence.
Mary: How much you lack?
John: I'm nearly done. I have about 30 minutes left.
The thing that, more often than not, determines whether you get hired or promoted.
It’s not always what you know, but who you blow.
What parents say to get a rise out of you
Ahh, Before you were born the good ol days
The act of having impregnating a woman on a one night stand. And not showing up until the child's 18th birthday to say "Happy Birthday, you little bastard!"
Wow Kyle, took you long enough to Reap What You Sow
Oh thats right you cant even produce come to because you have a push
Oh thats right you cant even produce come to because you have a push