barbells vs. dumbells

How should the percentage of weight that I press with dumbells relate to the percentage of weight I press with a barbell? For example, I use 90lbs DBs, but my bench press is around 220. How does this relate? Unnastand? peace

C Poliquin said in an article or one of his columns that it should be half of 90% of the barbell weight. So if you can do 200 on a bar, 90% of that is 180 & half of that is 90. That means 90lb dumbells.

So, with that in mind, I should be pressing around 72lb dumbbells? I bench 160lbs, but have been performing incline dumbbell presses with 60lbs. However I’ll try the flat bench dumbbell presses - 70lbs should not be a problem.