Mortgage (and other loan) qualification is increasingly being done by means of "credit scoring". This is a mathematical analysis which considers many different aspects of your credit history -- late payments, delinquencies, tax liens, etc... and expresses it as a single "grade". This calculator will "grade" your credit using the number of late payments you have on various credit accounts. This isn't a true "credit score", but will give you a pretty good idea of your credit worthiness.
If you are ready to start your buying or selling process
give me a call. I'm happy to answer all your questions.