GraduateLedger

Tool

Quarterly estimated tax estimator

If nothing is withheld from your stipend or fellowship, the IRS expects four payments a year. Enter your expected income and last year’s tax to see whether you need to pay, how much, and by when.

Estimate, not tax advice. Federal tax only, tax year 2026, single filer, standard deduction, equal payments. Self-employment tax, credits and state estimated tax are not included. Nothing you enter is sent to us. See our methodology and disclaimer.

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The rules it applies

Source: IRS Publication 505, chapter 2 (checked October 2026), and Form 1040-ES.

  1. Do you need to pay? Generally yes if you expect to owe $1,000 or more after subtracting withholding and credits. Below that, no estimated payments and no penalty.
  2. How much is enough? Paying the smaller of 90% of this year’s tax or 100% of last year’s tax through withholding and estimated payments combined avoids the underpayment penalty. If last year’s adjusted gross income was over $150,000, the second figure is 110% of last year’s tax. (Married filing separately has a $75,000 threshold; this tool does not model that filing status.)
  3. The no-tax-last-year exception. If you owed no tax last year, were a U.S. citizen or resident for all of last year and last year was a full 12-month year, you are generally not required to pay estimated tax this year. You may still owe at filing.
  4. The 2026 dates. April 15, June 15 and September 15, 2026, and January 15, 2027. The fourth payment can be skipped if you file your 2026 return by January 31, 2027 and pay everything you owe.

What the tool does not do

It assumes equal payments. If your income is lumpy (a fall fellowship and a big summer stipend, say), the annualized income installment method on Form 2210, Schedule AI may lower what you owe for earlier dates. It does not compute self-employment tax on side income, state estimated tax, or the underpayment penalty itself. International students on F-1 or J-1 visas often have tax withheld already; see our international student tax guide.

For the full explanation, read The Quarterly Tax Deadline No One Warns Grad Students About and Yes, Your Stipend Is (Probably) Taxable. For monthly take-home, use the stipend budget calculator.