Keelsheet
Free Q4 2026 estimated tax worksheet
Work out your January 15, 2027 estimated tax payment on one page. 25 lines, 2026 IRS figures, the safe harbor built in. Print it or use the spreadsheet; no email required.
Google Sheets: File > Import > Upload, then pick the file. Yellow cells are inputs; the example numbers are fictional.
Keelsheet Q4 2026 Estimated Tax Worksheet
Payment due Friday, January 15, 2027. Scope: one sole-proprietor business, standard deduction. Planning estimate, not tax advice.
| Line | Item | Yours | Example |
|---|---|---|---|
| 1 | Filing status (Single, MFJ or HOH) | Single | |
| 2 | Expected 2026 net profit (Schedule C line 31) from a business you materially participate in (you run it yourself) | $60,000.00 | |
| 3 | Other 2026 taxable income (W-2 box 1, interest; spouse wages if MFJ) | $0.00 | |
| 4 | Your W-2 Social Security wages (box 3) | $0.00 | |
| 5a | Business adjustments (SEP or solo 401(k), SE health insurance); these also reduce QBI | $0.00 | |
| 5b | Other adjustments (HSA, student-loan interest) | $0.00 | |
| 6 | Federal tax withheld in 2026 | $0.00 | |
| 7 | Estimated payments already made for 2026 | $6,000.00 | |
| 8 | Your total 2025 tax (2025 Form 1040 line 24, minus refundable credits); leave blank if your 2025 return covered less than 12 months | $9,000.00 | |
| 9 | 2025 AGI over $150,000 ($75,000 if married filing separately)? Y/N | N | |
| 9a | Extra 2026 deductions: the higher standard deduction for age 65+ or blind ($2,050 each unmarried, $1,650 each married), cash gifts to charity (up to $1,000, $2,000 MFJ) and the Schedule 1-A amounts you figured (tips, overtime, car-loan interest, and the senior deduction: up to $6,000 per person 65 or older, $12,000 if both spouses qualify, reduced above $75,000 of modified AGI, $150,000 MFJ) | $0.00 | |
| 9d | Part of line 9a that is qualified tips from this business (they come out of QBI; leave employee tips out) | $0.00 | |
| 9b | Nonrefundable credits (child tax credit, nonrefundable part of education credits) | $0.00 | |
| 9c | Refundable credits (net premium tax credit after advance payments, refundable part of the child tax credit or the American opportunity credit, up to 40% of it) | $0.00 | |
| 10 | SE earnings: line 2 × 92.35% | $55,410.00 | |
| 11 | Social Security part: 12.4% of line 10, up to $184,500 minus line 4 | $6,870.84 | |
| 12 | Medicare part: 2.9% of line 10 | $1,606.89 | |
| 13 | Self-employment tax: 11 + 12 | $8,477.73 | |
| 14 | Adjusted gross income: 2 + 3 − half of 13 − 5a − 5b | $55,761.14 | |
| 15 | Deductions: standard deduction ($16,100 single, $32,200 MFJ, $24,150 HOH) + line 9a | $16,100.00 | |
| 16 | Taxable income before QBI deduction: 14 − 15 | $39,661.14 | |
| 17 | QBI deduction: 20% of (2 − half of 13 − 5a − 9d), capped at 20% of line 16, $400 minimum when that QBI is $1,000 or more and you materially participate | $7,932.23 | |
| 18 | Taxable income: 16 − 17 | $31,728.91 | |
| 19 | Income tax from the 2026 rate schedule (table below) | $3,559.47 | |
| 20 | Total expected 2026 tax: 19 − 9b (not below zero) + 13 − 9c | $12,037.20 | |
| 21 | 90% of line 20 | $10,833.48 | |
| 22 | Prior-year safe harbor: line 8 (× 110% if line 9 is Y) | $9,000.00 | |
| 23 | Required annual payment: smaller of 21 and 22 | $9,000.00 | |
| 24 | Your Q4 payment for the safe harbor: 23 − 6 − 7 (zero if line 20 − line 6 is under $1,000) | $3,000.00 | |
| 25 | Q4 payment to cover the full estimate: 20 − 6 − 7 | $6,037.20 |
2026 rate schedule for line 19 (tax on each slice of line 18)
| Rate | Single | Married filing jointly |
|---|---|---|
| 10% | $0 to $12,400 | $0 to $24,800 |
| 12% | to $50,400 | to $100,800 |
| 22% | to $105,700 | to $211,400 |
| 24% | to $201,775 | to $403,550 |
| 32% | to $256,225 | to $512,450 |
| 35% | to $640,600 | to $768,700 |
| 37% | over $640,600 | over $768,700 |
Head of household brackets are in the spreadsheet and in the 2026 Form 1040-ES. Skip-Q4 rule: file your 2026 return and pay in full by February 1, 2027 and no January payment is needed. Example: earlier quarters were $250 short each, so a penalty of about $29 still applies to them (see missed payment guide). keelsheet.com
How to use it
- Total your profit so far this year and add a realistic guess for November and December.
- Find your 2025 total tax on your 2025 Form 1040 (line 24). That sets the prior-year safe harbor.
- Fill lines 1 to 9, including 9a, 9d, 9b and 9c. The spreadsheet does the rest; on paper, follow the formulas on each line.
- Pay line 24 by January 15, 2027 through your IRS Online Account or IRS Direct Pay. Step by step: how to pay estimated taxes online.
More on the January payment: Q4 2026 estimated tax payment guide. Prefer a calculator? Use the free quarterly estimated tax calculator.
Plan all four payments next year
The worksheet handles one payment. The Keelsheet Tax Bundle tracks income and expenses by Schedule C line all year and lays out every 1040-ES payment with the safe-harbor minimum. Excel + Google Sheets, one-time purchase.
14-day refund if it doesn't work as described.
FAQ
Is this worksheet free?
Yes. Print it, or download the Excel file and open it in Excel or Google Sheets (File > Import). No email is required. You can join the deadline reminder list if you want an email before each due date.
Which tax year does it cover?
Tax year 2026, the year the January 15, 2027 payment belongs to. It uses the 2026 figures from IRS Form 1040-ES: the $16,100 single standard deduction, the 2026 brackets and the $184,500 Social Security wage base.
Do I have to make the January 15 payment?
Not if you file your 2026 return by February 1, 2027 and pay the entire balance with it (Form 1040-ES instructions). Otherwise pay enough by January 15 to reach the safe harbor on line 23.
What does it leave out?
State tax, the 0.9% Additional Medicare Tax, itemized deductions, capital gains and qualified dividends, and QBI limits above $201,750 of taxable income ($403,500 married filing jointly). If any apply, use the full Form 1040-ES worksheet or a tax professional.
Optional
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