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 Federal Income Tax Use this calculator to estimate your income tax liability along with average and marginal tax rates. Red Flags for Tax Auditors Here are six flags that may make your tax return prime for an IRS audit. Capital Gains Tax Estimator Use this calculator to estimate your capital gains tax.