2021 Social Security Benefits Calculator (Excel based)

Description
Objective / Features - This file allows you to:
1) Estimate monthly Social Security benefits at retirement.
2) Perform scenario analysis including (but not limited to):
-"What would my benefits be if I filed today?" At 67 (normal retirement age)? Earlier than 67? At 67 and 4 months?"
-"How would my benefits change if inflation was 3% per year? 5% per year? 3% per year and the average wage grew by 2% per year?"
-"How would my benefits change if I worked for 3 more years?"
-"How would my benefits change if I took a better paying job?"
-etc


Directions:
1) Go to the "Model" tab
2) Enter your information in Column M (orange cells only). Note:
-Economy Assumption uses Medium Growth as the default. More on this below
-Retirement Date is when you file for Social Security benefits, not when you stop working (FI/RE folks, take note!)
3) Enter your annual wage history in Column B (You can get this from www.ssa.gov)
4) Your estimated monthly benefit will be in Cell M10 (Bonus: The Social Security taxes paid over your lifetime will be in Cells M13-M15)

Economy Assumptions: The U.S. Social Security Administration uses three scenarios in their annual trustees report. These are:

1) Alternative I, their optimistic scenario. This model calls this the "High Growth" economy.
2) Alternative II, their intermediate scenario. This model calls this the "Medium Growth" economy. If you've ever estimated your benefits at ssa.gov or elsewhere, this scenario is used.
3) Alternative III, their pessimistic scenario. This model calls this the "Low Growth" economy.
Assumptions used in each scenario are located in the "Economy" tab.
Enter your own scenario! Do you disagree with these assumptions? Would a $988K average wage in 2100 be absurd? Select "Custom" and edit Columns B-C in the "Custom" tab.