How we calculate
Every calculator on this site uses the same tax engine and the same set of 2026 figures. They were last checked on September 28, 2026. Here’s exactly what they do.
What’s included
- Federal self-employment tax (Schedule SE)
- Federal income tax with the standard deduction and 2026 brackets
- The deduction for half of self-employment tax
- The 20% qualified business income (QBI) deduction, simplified
- The qualified tips deduction (2025–2028), when you choose it
- The IRS standard mileage rates
What’s not included (yet)
- State and local income taxes
- Tax credits (child tax credit, earned income credit and others)
- Itemized deductions, the self-employed health insurance deduction and retirement contributions
- Capital gains and other special income
Because credits aren’t included, some people, especially lower earners with children, will owe less than our estimate.
Step by step
- Net profit = business income − business expenses (including the mileage deduction).
- Net earnings from self-employment = net profit × 92.35%. Under $400, no SE tax is due.
- Social Security = 12.4% × net earnings, on up to $184,500 minus any W-2 wages.
- Medicare = 2.9000000000000004% × net earnings, plus 0.8999999999999999% Additional Medicare Tax on earnings above $200,000 ($250,000 married filing jointly), less W-2 wages.
- Adjusted gross income = W-2 wages + other income + net profit − half of SE tax (excluding Additional Medicare Tax).
- Taxable income = AGI − standard deduction − tips deduction − QBI deduction.
- Income tax from the 2026 brackets below.
When you enter W-2 wages, results show the extra tax caused by your self-employment income: total tax minus the tax on your wages alone.
QBI deduction
20% of qualified business income (net profit minus half of SE tax), limited to 20% of taxable income before the deduction. Above $201,750 of taxable income ($403,500 joint), we reduce it in a straight line to zero over $75,000 ($150,000 joint). This assumes the business has no W-2 employees and no significant business property, which is true for most solo gig workers and freelancers.
Tips deduction
Up to $25,000 of qualified tips, reduced by $100 for each $1,000 of income above $150,000 ($300,000 joint), and limited to net profit. It lowers income tax only.
Quarterly payments
Required payment = the lower of 90% of this year’s estimated tax, or 100% of last year’s tax (110.00000000000001% if last year’s AGI was over $150,000). We subtract withholding and payments already made and divide the rest evenly across the due dates that haven’t passed.
2026 figures
Standard deduction
| Filing status | Amount |
|---|---|
| Single | $16,100 |
| Married filing jointly | $32,200 |
| Head of household | $24,150 |
Tax brackets: Single
| Rate | Taxable income |
|---|---|
| 10% | $0 – $12,400 |
| 12% | $12,400 – $50,400 |
| 22% | $50,400 – $105,700 |
| 24% | $105,700 – $201,775 |
| 32% | $201,775 – $256,225 |
| 35% | $256,225 – $640,600 |
| 37% | Over $640,600 |
Tax brackets: Married filing jointly
| Rate | Taxable income |
|---|---|
| 10% | $0 – $24,800 |
| 12% | $24,800 – $100,800 |
| 22% | $100,800 – $211,400 |
| 24% | $211,400 – $403,550 |
| 32% | $403,550 – $512,450 |
| 35% | $512,450 – $768,700 |
| 37% | Over $768,700 |
Tax brackets: Head of household
| Rate | Taxable income |
|---|---|
| 10% | $0 – $17,700 |
| 12% | $17,700 – $67,450 |
| 22% | $67,450 – $105,700 |
| 24% | $105,700 – $201,750 |
| 32% | $201,750 – $256,200 |
| 35% | $256,200 – $640,600 |
| 37% | Over $640,600 |
Mileage
| Period | Business rate |
|---|---|
| Jan 1 – Jun 30, 2026 | 72.5¢ per mile |
| Jul 1 – Dec 31, 2026 | 76¢ per mile |
Sources
- IRS: tax inflation adjustments for tax year 2026 (Rev. Proc. 2025-32)
- IRS: 2026 business standard mileage rate, and the mid-year increase to 76¢ effective July 1, 2026
- IRS Form 1040-ES (2026): estimated tax and due dates
- Social Security Administration: maximum taxable earnings
- IRS: Form 1099-K threshold FAQs
- IRS Schedule SE, Form 8995 (QBI) and Form 8959 (Additional Medicare Tax) instructions