What Is Taxable Income?
Quick Answer
Taxable income is the portion of your earnings that is actually subject to federal income tax. It is calculated by taking your total (gross) income and subtracting adjustments, deductions, and exemptions. For most workers, taxable income is significantly lower than their salary because of the standard deduction and pre-tax contributions like 401(k) and HSA. Taxable income is the number the IRS uses to determine which tax brackets apply to you.
How Taxable Income Is Calculated
The path from your paycheck to your taxable income follows these steps:
- Gross income — All income from wages, investments, side gigs, and other sources
- Minus above-the-line adjustments = Adjusted Gross Income (AGI)
- Minus deductions (standard or itemized) = Taxable income
Common Above-the-Line Adjustments
- Traditional 401(k) contributions
- HSA contributions
- Student loan interest (up to $2,500)
- Self-employment tax deduction (half of SE tax)
- Traditional IRA contributions
Real Example With Actual Numbers
Rachel earns a $95,000 salary in California. She is single, contributes $10,000 to her 401(k), and $4,300 to her HSA. Here is how her taxable income is calculated:
| Step | Amount |
|---|---|
| Gross salary | $95,000 |
| 401(k) contribution | -$10,000 |
| HSA contribution | -$4,300 |
| Adjusted Gross Income | $80,700 |
| Standard deduction | -$15,000 |
| Taxable income | $65,700 |
Rachel's salary is $95,000 but she only pays federal income tax on $65,700. That difference of $29,300 saves her thousands in taxes. At her marginal rate of 22%, the 401(k) and HSA alone save about $3,146 in federal tax.
You can see this breakdown for your own salary using the SalaryHog calculator.
What Counts as Gross Income
The IRS has a broad definition of income. Taxable income can come from:
- Wages and salary (your W-2 income)
- Self-employment income (1099 and freelance earnings)
- Bonuses and commissions
- Investment gains and dividends
- Rental income
- Side hustle income
- Unemployment benefits
- Imputed income from employer-provided benefits
Why Taxable Income Matters
Your taxable income determines:
- Which tax brackets apply — The bracket thresholds are based on taxable income, not gross income
- Your effective tax rate — A lower taxable income means a lower effective rate
- Eligibility for credits — Many tax credits phase out at certain income levels based on AGI or taxable income
- State taxes — Most states with income tax start with federal AGI or taxable income as their baseline. See how state taxes work
How to Reduce Your Taxable Income
The most effective strategies for lowering taxable income are:
- Max out your 401(k) — Up to $23,500 in 2025. See how a 401(k) reduces taxes
- Contribute to an HSA — $4,300 individual / $8,550 family in 2025
- Use an FSA — Up to $3,300 in 2025 for healthcare expenses
- Claim the right filing status — Head of household gets a larger standard deduction than single
Every dollar you remove from taxable income saves you money at your marginal rate. Use the calculator to model different contribution levels and see how they change your take-home pay.