I've never needed to check what it actually is. I run a couple of mortgages (one a buy-to-let), but apart from that debt, my credit cards are paid off monthly, I only use under a tenth of a high limit, and since I never fall behind on payments, there's nothing really to knock it down, I'm guessing.
Less than 1/10 of a high limit? They didn't like the 4% use on ours--and supposedly our total available revolving credit was $100K! I have no idea how it's that much with only 3 cards and none anywhere near that. And, as I and another posted, they don't care about your paying off every month, just how much you owe compared to available credit. And they may not like your 2 mortgages.
Someone posted a website that gives you a rough--really rough--idea. Mine said "765 to 815." That's pretty rough, I think. (We're at the highest end of that.)