Free US tax worksheet tool
US quarterly estimated tax calculator (2026 Form 1040-ES)
Estimate your 2026 required annual payment using the IRS Form 1040-ES and Publication 505 safe-harbor rules—the smaller of 90% of expected 2026 tax or 100% of 2025 tax (110% if 2025 AGI exceeded $150,000, or $75,000 if married filing separately for 2026)—subtract expected withholding, and split the balance into 4 equal quarterly payments across the 2026 due dates.
Estimate only, not tax advice: This page is a general mathematical estimate from the numbers you enter. It is not tax advice and does not tell you what you owe. Your entries stay in your browser and are never saved.
Estimate your 2026 Form 1040-ES quarterly payments
Enter your expected 2026 total tax, your 2025 total tax and 2025 AGI, and any expected 2026 federal income tax withholding to see how the IRS Worksheet 2-1 safe harbor splits across the four 2026 due dates.
2026 Form 1040-ES Estimated Tax Worksheet, line 11c (income tax + self-employment tax minus credits).
Total tax on your 2025 Form 1040 or 1040-SR, line 24 (adjusted per IRS Pub. 505 line 12b rules).
2025 Form 1040 or 1040-SR, line 11b. Determines whether the 100% or 110% prior-year rule applies.
The 110% higher-income threshold is $75,000 for Married filing separately and $150,000 for all other statuses.
Worksheet 2-1, line 13: federal income tax expected to be withheld from W-2 wages, pensions or annuities in 2026.
Estimated safe-harbor quarterly payment
$3,500.00
Split into 4 equal installments (Worksheet 2-1, line 15)
Estimated required annual payment (line 12c)
$14,000.00
Smaller of 90% of 2026 tax or 100% of 2025 tax
Estimated total after withholding (line 14a)
$14,000.00
Line 12c minus $0.00 expected withholding
| Payment period | 2026 tax year due date | Safe-harbor installment (¼ of line 14a) | Full expected balance (¼ of line 14b) |
|---|---|---|---|
| Q1 (Jan. 1 – March 31, 2026) | April 15, 2026 | $3,500.00 | $4,500.00 |
| Q2 (April 1 – May 31, 2026) | June 15, 2026 | $3,500.00 | $4,500.00 |
| Q3 (June 1 – Aug. 31, 2026) | September 15, 2026 | $3,500.00 | $4,500.00 |
| Q4 (Sept. 1 – Dec. 31, 2026) | January 15, 2027 | $3,500.00 | $4,500.00 |
| Line 11c: Expected 2026 total tax | Entered above | $18,000.00 |
|---|---|---|
| Line 12a: 90% of expected 2026 tax | $18,000.00 × 90% (0.90) | $16,200.00 |
| Line 12b: 100% of 2025 tax safe harbor | $14,000.00 × 100% (2025 AGI at or below $150,000) | $14,000.00 |
| Line 12c: Estimated required annual payment | Smaller of line 12a or line 12b | $14,000.00 |
| Line 14a: Required annual payment minus withholding | Line 12c minus $0.00 withholding | $14,000.00 |
| Line 15: Each regular quarterly installment | Line 14a ÷ 4 (when line 14b ≥ $1,000 and line 14a > $0) | $3,500.00 |
This worksheet calculation is an estimate based solely on the figures you enter. It is not tax advice and does not tell you what you owe. Even if you pay the safe-harbor required annual payment to avoid an underpayment penalty, you may still have a remaining balance due when you file your 2026 return. Special rules apply to farmers and fishers (66⅔% rule) and uneven seasonal income (Form 2210 annualized income installment method).
Official IRS examples
Worked examples from IRS Publication 505 (2026)
1. Higher-income 110% safe harbor (IRS Pub. 505, Ch. 2)
In IRS Publication 505 (2026), a taxpayer had $42,581 of total tax on their 2025 return, $180,000 of 2025 AGI, and $71,253 of expected tax for 2026. Because 2025 AGI was over $150,000, the prior-year safe harbor is 110% of 2025 tax ($42,581 × 1.10 = $46,839.10, or $46,839 rounded). Ninety percent of expected 2026 tax is $71,253 × 0.90 = $64,127.70 ($64,128 rounded). The required annual payment is the smaller of the two: $46,839.
2. Regular installment split into 4 payments (IRS Pub. 505, Ch. 2)
Under the Regular Installment Method example in IRS Publication 505 (2026), a taxpayer whose first payment is due April 15, 2026 figures an annual estimated tax due of $1,800 on line 14a of Worksheet 2-1. Dividing $1,800 by 4 produces four equal quarterly installments of $450.00 due April 15, 2026, June 15, 2026, September 15, 2026 and January 15, 2027.
Official IRS constants and source quotes
Every due date, percentage and AGI threshold used by this calculator comes directly from IRS Publication 505 (2026).
| Constant | Tax year | Value | Exact quote from source | Official source & date checked |
|---|---|---|---|---|
| 2026 estimated tax balance threshold ($1,000) | 2026 | $1,000 | “You expect to owe at least $1,000 in tax for 2026 after subtracting your withholding and tax credits.” | IRS Publication 505 (2026), Tax Withholding and Estimated TaxChecked 2026-11-05 |
| 2026 current-year safe-harbor percentage (90%) | 2026 | 90% | “The total amount you must pay is the smaller of: 90% of your total expected tax for 2026, or 100% of the total tax shown on your 2025 return. Your 2025 tax return must cover all 12 months.” | IRS Publication 505 (2026), Required Annual Payment—Line 12cChecked 2026-11-05 |
| 2026 prior-year safe-harbor base percentage (100% of 2025 tax) | 2026 | 100% | “100% of the total tax shown on your 2025 return. Your 2025 tax return must cover all 12 months.” | IRS Publication 505 (2026), Required Annual Payment—Line 12cChecked 2026-11-05 |
| 2026 higher-income prior-year safe-harbor percentage (110% of 2025 tax) | 2026 | 110% | “If your AGI for 2025 was more than $150,000 ($75,000 if your filing status for 2026 is Married filing separately), substitute 110% for 100% in (2) above.” | IRS Publication 505 (2026), Higher Income TaxpayersChecked 2026-11-05 |
| 2025 AGI threshold for 110% safe harbor (all filing statuses except Married filing separately) | 2026 | $150,000 | “If your AGI for 2025 was more than $150,000 ($75,000 if your filing status for 2026 is Married filing separately), substitute 110% for 100% in (2) above.” | IRS Publication 505 (2026), Higher Income TaxpayersChecked 2026-11-05 |
| 2025 AGI threshold for 110% safe harbor (Married filing separately for 2026) | 2026 | $75,000 | “If your AGI for 2025 was more than $150,000 ($75,000 if your filing status for 2026 is Married filing separately), substitute 110% for 100% in (2) above.” | IRS Publication 505 (2026), Higher Income TaxpayersChecked 2026-11-05 |
| Number of regular quarterly installments | 2026 | 4 | “If your first estimated tax payment is due April 15, 2026, you can figure your required payment for each period by dividing your annual estimated tax due (line 14a of the 2026 Estimated Tax Worksheet (Worksheet 2-1)) by 4.” | IRS Publication 505 (2026), Regular Installment MethodChecked 2026-11-05 |
| 2026 Form 1040-ES 1st installment due date (Jan. 1 – March 31 period) | 2026 | 2026-04-15 | “Jan. 1 – March 31 | April 15 | April 15, 2026” | IRS Publication 505 (2026), When To Pay Estimated TaxChecked 2026-11-05 |
| 2026 Form 1040-ES 2nd installment due date (April 1 – May 31 period) | 2026 | 2026-06-15 | “April 1 – May 31 | June 15 | June 15, 2026” | IRS Publication 505 (2026), When To Pay Estimated TaxChecked 2026-11-05 |
| 2026 Form 1040-ES 3rd installment due date (June 1 – Aug. 31 period) | 2026 | 2026-09-15 | “June 1 – Aug. 31 | Sept. 15 | Sept. 15, 2026” | IRS Publication 505 (2026), When To Pay Estimated TaxChecked 2026-11-05 |
| 2026 Form 1040-ES 4th installment due date (Sept. 1 – Dec. 31 period) | 2026 | 2027-01-15 | “Sept. 1 – Dec. 31 | Jan. 15, next year | Jan. 15, 2027” | IRS Publication 505 (2026), When To Pay Estimated TaxChecked 2026-11-05 |
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