No, it doesn't. Social security isn't a fixed amount, its based on prior earnings, adjusted by a wage index since the time they were earned, put through formula to get a base benefit amount in the year you start drawing them, and then inflation adjusted after retirement.

So calling a UBI "Social Security for everyone" does not, in fact, tell you what the benefit amount would be -- if the benefit amount is calculated anything like Social Security, the program is nothing like a UBI.