D&D 5E What is the CR value for a AC of 20?

[Athinar]

What is the CR value for a AC of 20 or the Value of AC of 23?

Hobgoblin Warlord has a CR 6 and a AC of 20 without the Parry

used the Parry to equal 1.5 times the Hps, but I know that is wrng

 

[MechaPilot]

AC 20 is not on the monster creation by CR table in the DMG.

 

[GX.Sigma]

The way the system works, you're not meant to find the creature's AC on the table. Find the hit points, and compare your AC to the default one for that CR. For every 2 points higher your AC is than the one suggested by the CR, you increase the defensive CR by 1.

The Warlord has 97 hp (default for CR 2). The default AC for CR 2 is 13. The Warlord has an effective AC of 21, which is 8 points higher, so the defensive CR increases by 4, giving us CR 6. The offensive CR also works out to 6, so we determine that this is a CR 6 creature.

 

[Athinar]

Thank you, I have been doing that wrong, I was using the CR, (CR 2), then find the CR of the AC, then find the difference of the CR

I now have to correct my Excel Spreadsheet