Today, February 28, is the first day this year that a millionaire stops contributing to Social Security. Most workers know that Social Security is financed through a tax on their earnings, but what many don’t know is that the tax only applies to the first $160,200 of earnings per year. This means that while most Americans will pay 6.2 percent of their annual earnings into the fund, a millionaire’s effective tax is less than 1 percent — and far less for the country’s superrich.

Center for Economic and Policy Research’s (CEPR’s) Sarah Rawlins has created a calculatorator that allows users to enter any person’s annual earnings and see when they would stop paying into Social Security, the percentage of their earnings subject to the tax, effective tax rate, total amount of tax levied, and the amount of additional taxes that would be levied were the tax cap lifted.

To accompany the calculator, Rawlins wrote a brief explainer on the ways in which the current cap is part of the problem when it comes to the projected shortfalls of the fund. The cap places the burden on the vast majority of Americans while the nation’s highest earners evade their fair share. By “scrapping the cap,” Congress can make a significant stride toward saving Social Security.

This post was originally published on Common Dreams.