found this chart with all the work done that shows you what percentage a survivor will get if they take survivor early and their spouse filed early for ss .
typically if the spouse took ss early they get a reduction on their ss benefit , but if they die and the surviving spouse files early for survivor they would get a double cut that is nasty .so there is what is called the widow limit . that is you get the higher of the two :
either the benefit with the double cut or the spouse who died , fra amount , with a reduction if they take survivor early . the widow limit keeps you from being hit to hard with a double reduction for 2 early filer's .