The tax code does not define an effective tax rate, so the result depends on the income you divide by. Taxable income, adjusted gross income (AGI) and gross income each give a different rate. When you quote one, say which income you used.
Take a single filer with $116,100 of wages and no other income in 2026. The $16,100 standard deduction brings their taxable income to $100,000. At the 2026 rates, their federal income tax is $16,712: $5,800 plus 22% of the $49,600 above $50,400. Divided by taxable income, that is an effective rate of 16.7%. Divided by gross income, it is 14.4%, and AGI gives the same 14.4% because they have no adjustments. These figures count federal income tax only, before credits, with no Social Security, Medicare or state tax.
An effective rate is not your tax bracket. The same filer’s marginal rate is 22%, the rate on each extra dollar. Their average is lower because their first dollars are taxed at 10% and 12%.
Sources
- IRS, Rev. Proc. 2025-32 (2026 inflation adjustments)
- 26 U.S.C. § 1, Tax imposed
- IRS, Federal income tax rates and brackets
Reviewed and updated September 2026. General information, not advice for your situation.