US Estimated Tax Calculator 2026

You generally have to pay estimated tax if you expect to owe at least $1,000 in tax for 2026 after subtracting your withholding and refundable credits, and your withholding and credits will be less than the smaller of 90% of your 2026 tax or 100% of the tax shown on your 2025 return. In practice that captures the self-employed, partners, investors with substantial unearned income, and almost every American living abroad, because foreign employers do not withhold US tax at all.

The four instalments for the 2026 tax year are due on 15 April 2026, 15 June 2026, 15 September 2026 and 15 January 2027. Each of those dates falls on a weekday, so none of them shifts. Note that the periods they cover are not equal: the second instalment covers only April and May, which is why the gap between the first two payments is two months rather than three.

You avoid the underpayment penalty if you pay at least 90% of the tax shown on your 2026 return, or 100% of the tax shown on your 2025 return, whichever is less. Where your 2025 adjusted gross income exceeded $150,000, you substitute 110% for 100%, and that threshold is $75,000 if you file as married filing separately. The prior-year route is the more valuable of the two because it is a known number, whereas 90% of the current year can only ever be an estimate.

No, and this is the most common and most expensive misreading of the rule. The automatic two-month extension moves the date for filing your return and it does not move the statutory instalment dates, so your first payment is still due on 15 April. The IRS is explicit that even where an extension is allowed you must pay interest on any tax not paid by the regular due date of the return.

They reduce the liability you are estimating, which usually reduces the payments you need to make, but they do not reduce every part of the bill. The credit offsets your income tax only. It cannot be set against self-employment tax and it cannot be set against the 3.8% Net Investment Income Tax. A wealthy American in Britain can therefore hold enough credit to wipe out the income tax and still owe five figures of estimated tax on investment income alone, which is precisely the case this calculator models.

The Net Investment Income Tax is charged under a different chapter of the code from the income tax that the foreign tax credit relieves, so UK tax on the same dividends and gains gives you nothing against it. The charge is 3.8% on the smaller of your net investment income or the amount by which your modified adjusted gross income exceeds $200,000 for single filers, $250,000 for joint filers, or $125,000 for married filing separately. Since nothing shelters it, it flows straight into your quarterly payments.

Generally not. Unlike most other penalties, the underpayment of estimated tax penalty cannot ordinarily be removed for reasonable cause, which is a distinction that catches out taxpayers who assume a good explanation will fix it. The narrow exceptions cover a casualty or disaster, retirement after reaching 62, disability, and income that arrived unevenly during the year. Relying on any of them is far harder than simply meeting the prior-year safe harbour in the first place.

It is interest rather than a flat fine. The IRS applies the published quarterly underpayment rate to each unpaid instalment, running from the date that instalment fell due until it is paid or until the return due date, whichever comes first. The underpayment rate for non-corporate taxpayers has been 7% for most of 2026, so missing every instalment costs roughly 4.5% to 5% of the required annual payment. This calculator applies that method rather than a single flat percentage.

By default, no. Tax withheld during the year is treated as paid in four equal instalments regardless of when it was actually deducted, which usually helps you because a large deduction late in the year is spread backwards. You may instead elect to treat it as paid on the dates it was genuinely withheld, which is occasionally the better answer. This calculator uses the default even-spreading rule.

You can use the annualised income instalment method, worked on Schedule AI of Form 2210, which recalculates each required instalment by reference to the income actually received by that point in the year. It is materially more work than four equal payments, but it is the correct answer where a business sale, a bonus or a large capital gain lands in the autumn. Without it you would be penalised for not having paid tax in April on income that did not yet exist.

Britain runs its own instalment system on a different rhythm. Payments on account fall due on 31 January and 31 July, and each is usually half of the tax you owed for the previous year. They are not required if your last Self Assessment bill was under £1,000, or if more than 80% of your tax for that year was collected at source. Combined with the four US dates, a cross-border taxpayer is managing six payment dates a year across two calendars.

The UK tax year ends on 5 April and the US tax year ends on 31 December, so the payments you make to HMRC rarely land in the US calendar year against which you want to credit them. On the cash basis a January payment on account and a July payment on account can both fall into one US year, doubling the credit available in that year and leaving the next year exposed. Modelling both calendars together, rather than each in isolation, is the single most useful thing a cross-border taxpayer can do in the autumn.

Yes, unless a totalisation agreement moves you out of the US system. Self-employment tax is charged at 15.3% on 92.35% of net profit and nothing is withheld at source, so it is collected through the same quarterly instalments as your income tax. Where a certificate of coverage places you in UK National Insurance instead, the US charge disappears altogether, which is why this calculator offers that as an option rather than assuming it.

It reduces your income tax, so it reduces the liability the instalments are based on, but it does not touch self-employment tax at all. The result is a familiar pattern: a self-employed American abroad projects no income tax, concludes that no estimated payments are needed, and then discovers a substantial self-employment tax bill that has been accruing interest since April. Enter your profit in this calculator to see the figure that survives the exclusion.

You will owe the underpayment interest on each instalment you skipped, and where the return is filed late you may also face the separate failure-to-pay penalty on top. The interest is not enormous in isolation, but it is entirely avoidable, and it is charged even where you are ultimately due a refund on some other basis. Meeting the prior-year safe harbour costs nothing beyond making the payments earlier.

The IRS accepts electronic payments through its own direct payment service and the Electronic Federal Tax Payment System, both of which generally require a US bank account. Taxpayers abroad who no longer hold one usually pay by debit or credit card through an approved processor, or by international wire, and should allow for the additional days those routes take. Whatever the method, the payment must reach the IRS by the due date, not merely be initiated by it.

For anyone with volatile or foreign income, the prior-year figure is usually the better choice, because it is fixed and knowable in April rather than dependent on an exchange rate and a foreign tax bill that will not be settled until the following January. If your income has fallen sharply this year, the 90% route may be cheaper, and you can switch to it. This calculator shows both and uses the smaller, which is what the rule permits.

You are expected to revise it. If your circumstances change after the first instalment, you recalculate the remaining payments so that the total for the year still meets a safe harbour, rather than leaving the original schedule in place. A mid-year sale, a change in filing status, or the loss of a foreign tax credit all justify re-running the numbers, and doing so in September is far cheaper than discovering the shortfall in April.

No. It models federal income tax, self-employment tax and the Net Investment Income Tax only. Several states run their own instalment regimes with their own thresholds and their own penalties, and a number of them, California among them, give no relief at all for foreign taxes paid. If you retain a filing obligation in a state after moving abroad, that liability needs to be estimated separately.

It uses the official 2026 brackets and standard deductions, the 2026 Social Security taxable maximum of $184,500, the statutory safe harbour percentages and the current 7% underpayment rate, and it applies the foreign tax credit only where the credit is actually allowed. It does not model itemised deductions, credits such as the child tax credit, the alternative minimum tax, or state tax. For a cross-border position with meaningful investment income, treat the output as a well-founded planning figure rather than a filed number.