Debt to Credit Ratio

I just went to Annualcreditreport.com and according to them DH's debt to credit ratio is 65%,however when I went to an online Debt Ratio calculator,the debt ratio was calculated to be 16%,is there a difference between debt to credit ratio and debt ratio,what am I missing here? What would be a "good" one when refinancing?
Btw-had to dish out $15.95 to see the credit score,that $ went up! :x
What credit score do you have to have these in order to qualify for the current interest rate for a re-fi?
Thanks in advance!

 

i work pt for a mortgage company and you need at least a 620 middle score to qualify

 

Is that the average score after consulting all three credit score companies?

 

no they use the middle score, they use equifax first and if its enough they use that

 

Equifax is also the one I went to,thanks!