The Social Security benefit formula is more complex than most people realize — and that complexity has real consequences for how much workers receive in retirement, and how proposed reforms would affect people at different income levels.
This tool lets you explore how the formula works. Draw your own earnings history or upload a CSV file with your actual wages, set your birth year and retirement age, and the tool will estimate your Average Indexed Monthly Earnings (AIME), Primary Insurance Amount (PIA), and replacement rate — the share of your earnings that Social Security replaces. For context, the tool also shows where low, medium, high, and maximum earners land under the current formula.
The tool also includes a simple reform simulator. Click “Edit formula” on the PIA chart to adjust the bend points and replacement rates, and see immediately how changes to the formula would affect workers at different income levels. The tool doesn’t include options for more complex policy reforms, such as changing the wage indexing factor, retirement ages, or the like; the goal of this tool is to help explain how the core retirement benefit formula works.
The calculations follow Social Security Administration (SSA) methodology, with earnings indexed to the year you turn 60 and benefits computed using the standard bend point formula. Projected values for future birth years use intermediate assumptions from the 2025 Social Security Trustees Report. The information here should be considered illustrative, not official SSA estimates. The results are approximate (i.e., don’t include many detailed adjustments like the family maximum) and are intended to help you understand how the formula works, not to replace the official SSA benefit calculators linked in the notes below.
If you’d like to learn more about Social Security, check out my series of YouTube videos where I explain key graphs and concepts to know about the program.
