I've been spoiled and haven't needed to use eUpgrade credits for travel recently, mostly ending up at the front of the plane on paid business-class tickets. So I'm a bit out of practice on upgrading. But on an upcoming trip I hope to upgrade from Premium Economy to Business, and I'm finding it pretty tricky to determine in advance the number of credits required.

The "Enhance your travels with special eUpgrade offers" page doesn't indicate the credit requirement for upgrading from PE. (And my ticket doesn't indicate the fare class for PE in any case. I gather it's O, but what the heck AC.)

And for the cases that apply to me, the "Viewing eUpgrade requirements" page lists a minimum number of credits required ("eUpgrades starting at"), but doesn't provide the actual number for specific distances.

I've been staring at this for a long time. What am I missing?