How do you calculate your debt to credit ratio?

Or is it credit to debt ratio? Either way, I am a college student with 1k of bad marks on my credit report from years ago.

I want to get a secured credit card for the amount that would look good to lenders like “this person pays on time and has a valuable credit history w/some lenders” (ie my dell account is on there which is good and the secured card would add to it).

Am I making sense? How can I do this? I’d rather not pay off the measley 1k, it should be removed within a few years anyway.

Pearl