Millions faithfully file their 1040 forms each April. But some things about federal income taxes may surprise you.

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.

Comparing Investments

This calculator compares the net gain of a taxable investment versus a tax-favored one.