“ “about $1,944 a month at full retirement age,” … let’s hope the cost of living doesn’t go up over the next thirty years.”
That’s (1) a “current dollars” estimate of your future benefit, (2) using current law assumptions about benefit levels, and with (3) some (can’t recall exactly) assumption about your likely future income.
factor 1 means the actual 2046 monthly benefit number will be considerably higher, as inflation means that $1,944 in 2016 dollars will be $[more] in 2046 dollars
factor 2 means that the actual 2046 month benefit will be lower, unless there is a substantial overhaul of the Social Security funding (that is, Tax) system — SS will be “broke” by then, and benefits paid will be limited to taxes paid in the current year, again, barring a change in law. That’s projected to be about a 15% reduction.
factor 3 means that if you have higher AGI in the future, you will have a higher starting benefit — the current max, at ‘full retirement age’ (67 for most here) is $ 2,639 — which is a healthy increase, but that involves 35 years of (inflation-adjusted) $100k+ average AGIs. 35 years of ~$60k average would indicate an expected ~$2,150 monthly benefit.