Social Security Taxes Estimate how much of your Social Security benefit may be considered taxable. You are viewing this website at a small screen resolution which doesn't support calculators. Click here to view this calculator. Share | Related Content The Facts About Income Tax Millions faithfully file their 1040 forms each April. But some things about federal income taxes may surprise you. How Income Taxes Work A quick look at how federal income taxes work. Comparing Investments This calculator compares the net gain of a taxable investment versus a tax-favored one.