How PlayStation Plus & PS Now Subs and Cards Convert to PS+ Premium

Those PlayStation Plus and PS Now cards all convert differently to the new PlayStation Plus Premium and the other tier levels.
Gonna need a calculator for this one

PlayStation Plus: Everything You Need to Know as Sony Makes Big Changes - CNET

How PlayStation Plus & PS Now Subs and Cards Convert to PS+ Premium

Sony Confirms it Has Suspended PS Plus and PS Now Subscription Stacking Until New PS Plus Launch

PlayStation Plus Extra/Premium Discounted, Ends Jan 13

How to use credit or debit cards on PlayStation Store

Sony May Have Revealed New Cheap Way To Get PS+ Premium [UPDATED]

PS+ subs bought on sale charged higher upgrade fees. Stacked subs must pay the upgrade fee for the entire duration. [Update: Sony Responds & Refunds] News, Page 23

PlayStation Plus membership conversions, explained

This $59.99 PS Now deal converts to new 740 game PS Plus Premium tier

Sony disables PlayStation Plus subscription stacking ahead of revamp - Polygon

Don't buy Sony's new yearly PS Plus Extra subscription, and here's why