Quarterly Tax Estimator (Self-Employed)
Deductible costs: software, equipment, home office, mileage, health insurance premiums are separate
Filing status
States set their own estimated-payment rules
Line 24 of last year's Form 1040, for the safe harbor
Last year's AGI above $150,000 ($75,000 married separately)?
Quarterly federal payments (2026)
$3,874 per quarter
Pays the full estimated federal tax of $15,495 through estimates.
Minimum to avoid an underpayment penalty (safe harbor): $3,486 per quarter, 90% of this year's tax. Any balance is due by April 15, 2027.
- April 15, 2026
- June 15, 2026
- September 15, 2026
- January 15, 2027
State estimate: about $871 per quarter ($3,485 a year).
How the federal tax adds up
| Net profit (income − expenses) | $75,000 |
|---|---|
| Self-employment tax (15.3% on 92.35% of profit) | $10,597 |
| Deduction for half of SE tax | −$5,299 |
| Standard deduction | −$16,100 |
| Qualified business income deduction (20%) | −$10,720 |
| Taxable income | $42,881 |
| Federal income tax (top bracket 12%) | $4,898 |
| Total federal tax | $15,495 |
Effective federal rate on profit: 20.7%. Self-employment tax is owed on top of income tax, which is why freelancers often set aside 25–35% of profit.
2026 brackets, standard deduction and Social Security wage base. Leaves out credits, itemized deductions, retirement contributions (SEP-IRA, Solo 401(k)) and the self-employed health insurance deduction, all of which lower the bill.
Estimate your 2026 quarterly estimated tax payments as a freelancer or small business owner: self-employment tax, federal income tax after the standard and qualified business income deductions, the safe-harbor minimum that avoids a penalty, a state estimate and the four due dates.
Formula
Worked Example
Self-employment tax on $75,000 of profit is $10,597. After deducting half of it, the $16,100 standard deduction and a $10,720 QBI deduction, taxable income is $42,881 and income tax $4,898. Together that is $15,495, or $3,874 a quarter.
Frequently Asked Questions
When are quarterly estimated taxes due in 2026?
April 15, June 15 and September 15, 2026, and January 15, 2027. The periods are uneven: the June payment covers April and May, and the September payment June through August.
How do I avoid an underpayment penalty?
Pay, through withholding and estimates, at least 90% of this year's tax or 100% of last year's total tax (110% if last year's AGI was over $150,000, or $75,000 married filing separately), spread evenly over the four dates. Owing less than $1,000 at filing also avoids the penalty.
What is self-employment tax?
The Social Security and Medicare tax an employer and employee would normally split, 15.3% in all, paid on 92.35% of your net self-employment profit. The 12.4% Social Security part stops at the wage base ($184,500 in 2026), and you deduct half of the total from your income.
Common Mistakes
- !Setting aside only the income tax and forgetting the 15.3% self-employment tax, which is often the larger amount for moderate profits.
- !Paying estimates on revenue instead of profit after business expenses.