How GigWorkerTax calculates
All figures are for the 2025 tax year (returns filed in 2026). This page lists the steps in the order the estimator applies them and every figure it uses. The tables are printed from the same code that does the calculation.
Sources for the 2025 figures (last checked October 1, 2026):
- Federal brackets, EITC maximum credits and income limits, QBI phase-in range: Rev. Proc. 2024-40
- Standard deduction: P.L. 119-21 (the 2025 tax law), which raised the amounts in Rev. Proc. 2024-40 for 2025; IRS, "How to update withholding to account for tax law changes for 2025"
- Child Tax Credit: P.L. 119-21 §70104; Rev. Proc. 2025-32
- Social Security wage base: Social Security Administration
- Standard mileage rate: IRS IR-2024-312
- SEP-IRA contribution cap: IRS Notice 2024-80
- Quarterly due dates: 2025 Form 1040-ES
1. Net earnings
Gross 1099 income minus business expenses. The deduction finder adds to expenses: mileage at $0.70 a mile, a home office at $5 a square foot up to $1,500 (the simplified method), the business share of your phone bill, and equipment. Source: IRS Publication 334, Publication 463, Publication 587.
2. Self-employment tax
15.3% of 92.35% of net earnings: 12.4% for Social Security up to the wage base of $176,100, and 2.9% for Medicare with no cap. Below $400 of net earnings there is no self-employment tax. Half of it is deducted in the next step. Source: Schedule SE.
An additional 0.9% Medicare tax applies to self-employment earnings over $200,000 (single) or $250,000 (married filing jointly). Source: Form 8959.
3. Adjusted gross income
Net earnings minus half of the self-employment tax, self-employed health insurance premiums (up to what is left), and SEP-IRA or Solo 401(k) contributions, which are capped at 20% of what is left and at $70,000. Source: Schedule 1, Publication 560.
4. Taxable income
Adjusted gross income minus the standard deduction ($15,750 single, $31,500 married filing jointly) and the qualified business income deduction. The QBI deduction is 20%, reduced in a straight line once taxable income passes $197,300 (single) or $394,600 (married) and gone at $247,300 or $494,600. You can switch it off. Source: IRC section 199A, Form 8995.
5. Federal income tax
Single
| Rate | Taxable income from | to |
|---|---|---|
| 10% | $0 | $11,925 |
| 12% | $11,925 | $48,475 |
| 22% | $48,475 | $103,350 |
| 24% | $103,350 | $197,300 |
| 32% | $197,300 | $250,525 |
| 35% | $250,525 | $626,350 |
| 37% | $626,350 | and up |
Married filing jointly
| Rate | Taxable income from | to |
|---|---|---|
| 10% | $0 | $23,850 |
| 12% | $23,850 | $96,950 |
| 22% | $96,950 | $206,700 |
| 24% | $206,700 | $394,600 |
| 32% | $394,600 | $501,050 |
| 35% | $501,050 | $751,600 |
| 37% | $751,600 | and up |
6. Credits
Child Tax Credit: $2,200 per child under 17, reduced by $50 for each $1,000 (or part of $1,000) of adjusted gross income over $200,000 (single) or $400,000 (married). It is applied up to your income tax; the refundable part (Additional Child Tax Credit) is not included. Source: Schedule 8812.
Earned Income Tax Credit: grows with earned income at 7.65%, 34%, 40% or 45% (by number of children) up to the maximum, then shrinks at 7.65%, 15.98% or 21.06% of the greater of adjusted gross income or earned income until the income limit. It is refundable, so federal tax can go below zero. Earned income here is net earnings minus half of the self-employment tax. Source: Publication 596.
| Children | Maximum credit | Income limit (single) |
|---|---|---|
| 0 | $649 | $19,104 |
| 1 | $4,328 | $50,434 |
| 2 | $7,152 | $57,310 |
| 3 or more | $8,046 | $61,555 |
| Children | Maximum credit | Income limit (married) |
|---|---|---|
| 0 | $649 | $26,214 |
| 1 | $4,328 | $57,554 |
| 2 | $7,152 | $64,430 |
| 3 or more | $8,046 | $68,675 |
7. State income tax
One rate times taxable income before the QBI deduction. The rate is a typical rate for your state, or the rate you enter. This is simpler than your state's own rules: it does not follow state brackets, state deductions, local taxes or state credits. Typical rates are based on the Tax Foundation's state income tax tables.
| State | Typical rate used |
|---|---|
| Alabama | 5.0% |
| Alaska | No income tax |
| Arizona | 2.5% |
| Arkansas | 4.9% |
| California | 6.4% |
| Colorado | 4.4% |
| Connecticut | 6.0% |
| Delaware | 6.6% |
| Florida | No income tax |
| Georgia | 5.5% |
| Hawaii | 8.0% |
| Idaho | 5.8% |
| Illinois | 4.9% |
| Indiana | 3.0% |
| Iowa | 5.7% |
| Kansas | 5.7% |
| Kentucky | 4.5% |
| Louisiana | 3.0% |
| Maine | 7.5% |
| Maryland | 5.5% |
| Massachusetts | 5.0% |
| Michigan | 4.3% |
| Minnesota | 7.0% |
| Mississippi | 4.7% |
| Missouri | 4.8% |
| Montana | 6.9% |
| Nebraska | 6.4% |
| Nevada | No income tax |
| New Hampshire | No income tax |
| New Jersey | 6.3% |
| New Mexico | 5.9% |
| New York | 8.5% |
| North Carolina | 4.5% |
| North Dakota | 2.5% |
| Ohio | 4.0% |
| Oklahoma | 4.7% |
| Oregon | 9.9% |
| Pennsylvania | 3.1% |
| Rhode Island | 6.0% |
| South Carolina | 6.4% |
| South Dakota | No income tax |
| Tennessee | No income tax |
| Texas | No income tax |
| Utah | 4.6% |
| Vermont | 6.6% |
| Virginia | 5.7% |
| Washington | No income tax |
| Washington D.C. | 8.5% |
| West Virginia | 6.5% |
| Wisconsin | 6.5% |
| Wyoming | No income tax |
8. Quarterly payments
Total tax (self-employment, federal, state and additional Medicare) divided by four, never below zero. Source: Publication 505, Form 1040-ES.
What is not covered
Itemized deductions, the alternative minimum tax, capital gains, W-2 wages, the refundable part of the Child Tax Credit, other credits, and state rules beyond one rate. The disclaimer explains what an estimate means.
It does not include the deductions added by the 2025 tax law for tips, overtime, car loan interest or people 65 and over.
Changes to the figures
- October 1, 2026. All figures moved to the 2025 tax year: standard deduction, Child Tax Credit, EITC income limits, QBI phase-in range, SEP-IRA cap and quarterly due dates.
- September 30, 2026. The SEP-IRA and Solo 401(k) limit for the self-employed is 20% of net earnings after half the self-employment tax (it was 25%).
Found a mistake?
Write to [email protected] with the inputs and the number you expected.