Quarterly payments
2026 Estimated Tax Calculator
Employees have tax withheld from every paycheck. The self-employed, investors with large gains, and anyone with untaxed income have to do that withholding themselves, in installments during the year. Fall far enough behind and the IRS charges interest on the shortfall even when the return itself shows a refund.
The test is not whether you eventually paid everything. It is whether you cleared one of two safe harbors along the way. Enter the tax you expect to owe, the tax shown on last year's return, and what has already been withheld, and the calculator returns the annual figure you must reach and what each installment needs to be.
Calculator
Official 2026 figures used here
| Expected 2026 tax | Prior-year tax | Required annual payment | Each of four installments |
|---|---|---|---|
| $10,000 | $10,000 | $9,000 | $2,250 |
| $20,000 | $20,000 | $18,000 | $4,500 |
| $40,000 | $40,000 | $36,000 | $9,000 |
| $40,000 | $20,000 | $20,000 | $5,000 |
| $20,000 | $40,000 | $18,000 | $4,500 |
How to read the result
The two safe harbors are not alternatives you choose between freely, because the smaller one governs. Paying 90% of this year's tax clears the first and paying 100% of last year's tax clears the second, so the required amount is the lower of the two. That is why the fourth row above is smaller than the third: a taxpayer whose income doubled can still pay against the prior year's smaller liability.
Withholding counts toward the requirement and is generally treated as paid evenly through the year rather than on the date it was taken. That makes it more forgiving than an estimated payment of the same size. Raising payroll withholding late in December can still fix the year, while a December estimated payment does not retroactively repair the earlier periods.
There is a floor beneath which none of this applies. If the balance due after withholding and refundable credits falls under the published minimum, no estimated tax is required at all. The tool checks that condition separately, because it can drive the answer to zero even when both safe harbors would otherwise demand a payment.
Uneven income has its own route. A taxpayer who earns most of the year's income inside one period can annualise the installments instead of paying four equal amounts, which lowers or eliminates the penalty for the earlier periods. That method needs its own schedule and sits outside this calculator, as do the special rules the IRS applies to certain higher income taxpayers, farmers and fishermen.
Questions people ask about this figure
What happens if I miss a quarterly payment?
The charge is interest on the amount that should have been paid, for the period it was late, rather than a flat fine. It applies even when the return shows a refund, because the test is timing rather than the final balance.
Do I have to pay estimated tax if I have a job?
Only if withholding will not cover the requirement. Many employees with side income raise withholding on a new Form W-4 instead of making separate installments, which avoids the timing problem altogether.
Is paying 100% of last year's tax always enough?
For most taxpayers yes, and it is the safer harbor when income is rising. The IRS notes special rules for certain higher income taxpayers, and this site does not publish the higher percentage because the pages consulted state that the rule exists without giving the figure.
Related calculators
Every figure on this page appears in the official release listed below. The values were checked against those pages on 2026-11-14. Where a release states a threshold but does not publish a rate, this site reports the threshold and does not estimate the missing value.
- IRS: Penalty for underpayment of estimated tax — Topic no. 306
- IRS: Estimated taxes — IRS estimated tax guide
- IRS: Publication 505, Tax Withholding and Estimated Tax (2026) — Publication 505 (2026)