Quarterly Estimated Tax Calculator

Do you need to pay quarterly?

Only if you expect to owe $1,000 or more for 2026 after withholding and credits. Below that there is no penalty to avoid (26 U.S.C. § 6654(e)(1)). A single filer with no other income passes that line at about $7,100 of profit, on self-employment tax alone, so a full year of 1099 work almost always crosses it.

A first year can be the exception. If you owed no federal tax at all for 2025, and 2025 was a full twelve months in which you were a US citizen or resident, there is no 2026 penalty whatever you pay (§ 6654(e)(2)). The tax is still due when you file.

How much to pay: the safe harbor rules

Each installment is a quarter of the required annual payment, which is the smaller of two figures (§ 6654(d)(1)): 90% of the tax on this year's return, or 100% of the tax on last year's. The second rises to 110% if last year's adjusted gross income was over $150,000.

On the example above, $105,000 of profit gives a full-year estimate of $23,889, and four payments of $5,973 pay all of it. The 90% test needs $21,500, which is four payments of $5,375, with the rest paid in April and no penalty on it. If last year's test, at 100% or 110% of your 2025 tax, comes to less than $21,500, a quarter of that is enough instead.

The same schedule is worked through for a single filer with no expenses at $50,000, $100,000 and $200,000 of profit.

The underpayment penalty and Form 2210

The penalty is interest, not a fine. It runs on each installment's shortfall from its due date until you pay it, or until the April filing deadline if that comes first, at the IRS underpayment rate, which is reset every quarter (26 U.S.C. § 6621). Paying a few days late costs a few days of interest.

You rarely have to work it out. The IRS computes it from your return and sends a bill. You file Form 2210 yourself only to ask for a waiver, to use the annualized method below, or where another box in its Part II applies (Instructions for Form 2210).

The last installment has relief of its own: file your 2026 return and pay everything due by the end of January 2027, and the January 15, 2027 payment carries no penalty (§ 6654(h)).

If your income arrives unevenly

Four equal payments assume the money comes in evenly. If most of it arrives late in the year, the annualized income installment method lets each payment follow what you had actually earned by the end of its period, so the early ones can be smaller (§ 6654(d)(2)). You claim it on Schedule AI of Form 2210 when you file.

How to pay

Online from a bank account with IRS Direct Pay, through EFTPS, or by check with a voucher from Form 1040-ES. Online, choose estimated tax as the reason and 2026 as the year.

With a W-2 job as well, you can raise your withholding instead, on a new Form W-4. Withholding counts as paid evenly through the year, whenever it was taken (§ 6654(g)), so extra tax taken from your last few paychecks can cover the whole year. For the rest of the picture, see the full 1099 tax breakdown.