PiggyQuarterly Estimated Tax Calculator (2026)
Estimate your total federal tax for the year — self-employment plus income tax — and see exactly what to send the IRS each quarter.
Your year
Tax breakdown
2026 payment deadlines
| Quarter | Period covered | Due date |
|---|---|---|
| Q1 | Jan 1 – Mar 31 | Apr 15, 2026 |
| Q2 | Apr 1 – May 31 | Jun 15, 2026 |
| Q3 | Jun 1 – Aug 31 | Sep 15, 2026 |
| Q4 | Sep 1 – Dec 31 | Jan 15, 2027 |
Never miss a deadline
How quarterly estimated taxes work
The U.S. tax system is pay-as-you-go. Employees have tax withheld from every paycheck; freelancers must instead send estimated payments four times a year using Form 1040-ES. This calculator combines your 2026 self-employment tax (15.3% on 92.35% of profit), federal income tax using the official 2026 brackets and standard deduction ($16,100 single / $32,200 married), the 20% qualified business income deduction, and your state's rate — then divides by four.
Two details this calculator gets right that quick estimates often miss. The QBI deduction is capped at 20% of your taxable income, not just 20% of profit, so at lower incomes it shrinks — ignoring that cap understates your bill by hundreds of dollars. And because every state defines its own deductions, the state figure applies your rate to profit after the self-employment tax adjustment, which errs slightly high: better to over-reserve than to be short in April.
To avoid an underpayment penalty, the IRS safe harbor is paying at least 90% of this year's tax or 100% of last year's (110% if your prior-year AGI topped $150,000). Every due date for both years is listed on our quarterly tax deadlines page, and the state-by-state guide shows which rate to enter above.