How to use this calculator
Enter your best estimate for the full 2026 tax year. The results update as you type.
- Net self-employment income: your business income minus business expenses, the profit you’d report on Schedule C.
- Filing status: single, married filing jointly, married filing separately or head of household. This sets your tax brackets, standard deduction and Additional Medicare Tax threshold.
- W-2 wages: pay from a job. Wages count towards the Social Security wage base, which can lower your self-employment tax.
- Other taxable income: interest, dividends, rental income and similar.
- Deduction: the standard deduction, or the total of your itemized deductions.
- Federal tax withheld: tax already taken from your paychecks this year. It reduces what you need to pay each quarter.
Example: $60,000 of freelance profit
Say you’re single, with $60,000 of net self-employment income and nothing else.
| 2026 estimate | |
|---|---|
| Self-employment tax | $8,477.73 |
| Federal income tax | $3,559.47 |
| Total federal tax | $12,037.20 |
| Each quarterly payment | $3,009.30 |
Your net earnings are $60,000 × 92.35% = $55,410, and self-employment tax is 15.3% of that. Half of it, $4,238.87, comes off your income, leaving adjusted gross income of $55,761.14. After the $16,100 standard deduction and a $7,932.23 qualified business income deduction, your taxable income is $31,728.91.
Notice that self-employment tax is more than twice your income tax here. Many new freelancers budget only for income tax and are caught out by this.
If you also earned $40,000 in wages with $3,000 withheld, and your side business made $30,000, your total federal tax would be $9,535.40. Withholding covers part of it, so each quarterly payment would be $1,633.85.
How it’s calculated
Self-employment tax (Schedule SE):
- Net earnings = profit × 92.35%. If that’s under $400, no self-employment tax is due.
- Social Security part = 12.4% × net earnings, up to the $184,500 wage base minus any W-2 wages.
- Medicare part = 2.9% × all net earnings.
Additional Medicare Tax = 0.9% of net earnings above your threshold ($200,000 single or head of household, $250,000 married filing jointly, $125,000 married filing separately), after your wages use up part of the threshold.
Income tax:
- Adjusted gross income = all income − half of self-employment tax.
- Subtract your standard or itemized deduction.
- Subtract the qualified business income deduction: 20% of profit after the deductible part of self-employment tax, capped at 20% of taxable income. Above the threshold for your filing status, the calculator phases it down to zero across the phase-in range, assuming no employees or business property. Taxpayers with at least $1,000 of qualified business income get a minimum $400 deduction.
- Apply the 2026 federal tax rates for your filing status.
Quarterly payment = (total tax − tax withheld) ÷ 4.
The estimate doesn’t include tax credits, the self-employed health insurance deduction, retirement contributions or state tax.
Tips for paying estimated tax
- Set aside money from every payment you receive. Moving a fixed share of each invoice into a separate account makes quarterly payments easier.
- Use the safe harbor if your income is uneven. Paying 100% of last year’s tax (110% if your 2025 AGI was over $150,000) in four equal parts generally avoids a penalty, even if this year turns out higher.
- Re-run the numbers mid-year. If your income changes, adjust your remaining payments rather than waiting for April.
- Consider retirement contributions. Contributions to a SEP-IRA or solo 401(k) can lower your income tax. They aren’t included in this estimate.
- Don’t forget your state. Your state may expect its own quarterly payments on different dates.
Frequently asked questions
Who has to pay quarterly estimated tax?
The IRS says that in most cases you must pay estimated tax for 2026 if you expect to owe at least $1,000 after subtracting withholding and refundable credits, and your withholding and credits will be less than the smaller of 90% of your 2026 tax or 100% of your 2025 tax.
When are the 2026 estimated tax payments due?
April 15, 2026; June 15, 2026; September 15, 2026; and January 15, 2027, according to the 2026 Form 1040-ES. You can also pay the whole year's estimated tax by April 15.
What is the self-employment tax rate?
15.3% of net earnings: 12.4% for Social Security, on earnings up to $184,500 in 2026, and 2.9% for Medicare, on all earnings. Net earnings are 92.35% of your profit. You can deduct half of the tax when working out your income tax.
How can I avoid an underpayment penalty?
Under the Form 1040-ES rules, you generally avoid it if your withholding and estimated payments cover at least 90% of your 2026 tax or 100% of your 2025 tax. If your 2025 adjusted gross income was over $150,000 ($75,000 if married filing separately), use 110% instead of 100%.
Does this calculator include state income tax?
No. It estimates federal tax only. Most states have their own estimated tax rules and payment dates, so check with your state's tax agency.
What is the qualified business income deduction?
It lets many self-employed people deduct up to 20% of their qualified business income, limited to 20% of taxable income. Above a 2026 threshold of $201,750 ($403,500 married filing jointly), the deduction depends on wages paid and the type of business; the calculator assumes no employees or business property.