About the Quarterly Estimated Tax Calculator
This quarterly tax calculator estimates how much federal tax you should send the IRS each quarter in 2026. It adds up your projected income tax and self-employment tax, subtracts anything already withheld from a paycheck, and splits the balance into four Form 1040-ES payments due April 15, June 15, September 15 and January 15.
It is built for freelancers, 1099 contractors, gig workers, landlords and anyone with side income that has no tax withheld. It also shows the safe-harbor payment: the minimum you can pay (90% of this year’s tax, or 100% of last year’s — 110% if your prior-year AGI was over $150,000) to avoid an underpayment penalty even if you end up owing more in April.
Figures use the 2026 federal brackets, standard deductions and the $184,500 Social Security wage base. The optional qualified business income (QBI) deduction is 20% of net profit less half of SE tax, phased out above $201,750 of taxable income ($403,500 joint) over the new $75,000 / $150,000 range, with the $400 minimum that starts in 2026 for at least $1,000 of active business income. It assumes you have no employees on payroll and no depreciable business property, so a high earner’s deduction phases out entirely; with staff or equipment your deduction could be larger. State estimated taxes, the SE health-insurance deduction and retirement contributions are not included.
With the default inputs, the quarterly payment (covers full projected tax) is $4,828.98. Change any value above to recalculate instantly.
How to use the quarterly estimated tax calculator
- 1Choose your filing status and enter the profit you expect from your business this year.
- 2Add any W-2 wages and the federal tax already being withheld from them.
- 3Enter itemized deductions only if they exceed the standard deduction.
- 4Enter last year’s total tax (or say you owed none) to see the penalty-proof safe-harbor amount.
- 5Pay each quarter by the due date shown using IRS Direct Pay or EFTPS.
Formula and method
Self-employment tax is 15.3% of 92.35% of your net profit (12.4% Social Security up to the $184,500 wage base, reduced by any W-2 wages, plus 2.9% Medicare, plus 0.9% Additional Medicare above $200,000 single / $250,000 joint). Half of the Social Security and Medicare portion is deducted from income.
Adjusted gross income minus the larger of your standard or itemized deduction, minus the optional QBI deduction, gives taxable income, which is run through the 2026 federal brackets. Withholding is subtracted and the remainder is divided into four equal payments. The safe-harbor figure is the smallest total you can pay on time to avoid the IRS underpayment penalty; it is zero if you had no tax liability for a full 2025 tax year.
QBI deduction = 20% × (profit − ½ SE tax), limited to 20% of taxable income before QBI. Above the threshold ($201,750; $403,500 joint; $201,775 separate) it shrinks by the fraction p = (taxable income − threshold) ÷ range ($75,000; $150,000 joint), assuming no W-2 wages paid and no qualified property; for a specified service business the QBI is also cut by p, so the deduction is multiplied by (1 − p)². If QBI is at least $1,000 the deduction is at least $400.
- SE tax
- Profit × 0.9235 × 15.3% (Social Security capped at the wage base)
- QBI
- 20% of qualified business income, capped at 20% of taxable income, phased out above the threshold, $400 minimum
- Safe harbor
- Minimum on-time payments that avoid the Form 2210 penalty
Worked examples
Single freelancer with $90,000 profit
SE tax is $90,000 × 92.35% × 15.3% ≈ $12,717, and half of it ($6,358) is deducted. Taxable income before QBI ($67,542) is far below the $201,750 threshold, so the full 20% QBI deduction of $13,508 applies, leaving about $54,033 taxable and $6,599 of income tax. The $19,316 total splits into four payments of about $4,829, but paying $4,000 a quarter (100% of last year’s $16,000) is enough to avoid a penalty.
Married couple: $60k side business plus $100k W-2 wages
SE tax on $60,000 is $8,478. Joint AGI is $155,761 after deducting half the SE tax; subtracting the $32,200 standard deduction and a $11,152 QBI deduction leaves $112,409 taxable, or $14,154 of income tax. After $9,000 of withholding, $13,632 remains — about $3,408 per quarter. Without last year’s figure the safe harbor is 90% of this year’s tax less withholding: about $2,842 a quarter.
High earner without QBI, 110% safe harbor
On $250,000 of profit, Social Security tax stops at the $184,500 wage base, so SE tax is $29,851 including $278 of Additional Medicare. Income tax on about $219,113 of taxable income is $46,572. Because prior-year AGI exceeded $150,000, the safe harbor is 110% of $60,000 = $66,000, or $16,500 per quarter.
Consultant in the QBI phase-out range
Taxable income before QBI is $209,247, which is $7,497 into the $75,000 phase-in range (p ≈ 10%). As a specified service business with no employees, the $45,069 tentative deduction is multiplied by (1 − p)² ≈ 0.81, giving about $36,509. Income tax is $34,055 and the 110% safe harbor is $55,000, or $13,750 a quarter.
New freelancer who owed no tax last year
On $30,000 of profit the SE tax is $4,239 and income tax $942, so paying about $1,295 a quarter covers the bill. Because the 2025 return showed no tax liability for a full year, no estimated tax penalty applies for 2026 even with no quarterly payments — the $5,181 is simply due with the return.
Frequently asked questions
When are 2026 quarterly estimated taxes due?+
Payments for tax year 2026 are due April 15, 2026, June 15, 2026, September 15, 2026 and January 15, 2027. If a date falls on a weekend or holiday, the deadline moves to the next business day.
Who has to pay quarterly estimated taxes?+
You generally must make estimated payments if you expect to owe at least $1,000 in federal tax after subtracting withholding and refundable credits — common for self-employed people, landlords and investors.
What is the safe harbor rule?+
You avoid an underpayment penalty if your withholding and timely estimated payments cover at least 90% of this year’s tax or 100% of last year’s tax (110% if last year’s AGI was over $150,000, or $75,000 if married filing separately).
What happens if I miss a quarterly payment?+
The IRS charges an underpayment penalty that works like interest on the amount that was short, calculated from the due date until you pay. It is figured on Form 2210 and is usually modest if you catch up quickly.
Can I pay more in one quarter if my income is uneven?+
Yes. If most of your income arrives late in the year, the annualized income installment method on Form 2210 Schedule AI lets you pay less in early quarters without a penalty.
How do I pay estimated taxes?+
Use IRS Direct Pay, EFTPS, a debit or credit card processor, or mail a check with a Form 1040-ES voucher. Your IRS online account shows every payment you have made.
Tax results are estimates based on published rules and simplified assumptions. They are not tax advice — check official guidance or a tax professional for your situation.