1099 Quarterly Estimated Tax Calculator

Why 1099 workers pay quarterly taxes

When you work for an employer, tax is withheld from every paycheck. When you’re paid on a 1099 — as a freelancer, independent contractor, gig worker or sole proprietor — nobody withholds anything. The IRS still expects tax to be paid as you earn, so self-employed people send estimated tax payments four times a year using Form 1040-ES. If you expect to owe $1,000 or more when you file and don’t pay enough during the year, you can be charged an underpayment penalty.

2026 estimated tax due dates

• 1st payment: April 15, 2026 (income earned Jan 1 – Mar 31, 2026)
• 2nd payment: June 15, 2026 (income earned Apr 1 – May 31, 2026)
• 3rd payment: September 15, 2026 (income earned Jun 1 – Aug 31, 2026)
• 4th payment: January 15, 2027 (income earned Sep 1 – Dec 31, 2026)

Note that the “quarters” aren’t equal: the second covers only two months and the fourth covers four. If a due date falls on a weekend or holiday, you have until the next business day.

How to use this calculator

1. Enter the 1099 and business income you expect for the whole year.
2. Enter your expected business expenses — software, equipment, a home office, mileage and so on.
3. Choose your filing status and, optionally, a flat state income tax rate.
4. Open the extra options if you also have a W-2 job or want to see your safe harbor payment.
5. Read your quarterly federal payment and the full breakdown below it.

How the estimate is calculated

First, your net profit (income minus expenses) is multiplied by 92.35% to get net earnings from self-employment. Self-employment tax is 12.4% Social Security on earnings up to the 2026 wage base of $184,500, plus 2.9% Medicare on all of it. Half of that SE tax is deducted from your income to get your adjusted gross income.

Next, the 2026 standard deduction — $16,100 for single filers, $32,200 for married couples filing jointly and $24,150 for heads of household — is subtracted. If selected, the qualified business income (QBI) deduction takes off up to 20% of your business profit (limited to 20% of taxable income). What’s left is taxed using the 2026 federal brackets from 10% to 37%. Your total federal tax is the income tax plus the SE tax, and each quarterly payment is a quarter of that.

The calculator also applies the 0.9% Additional Medicare Tax to high earners. It assumes you take the standard deduction and have no tax credits, and it doesn’t model QBI limits for specified service businesses above the income thresholds, so treat the result as a planning estimate.

Avoiding penalties with the safe harbor rule

Your income can be hard to predict. The IRS lets you avoid the underpayment penalty if you pay the smaller of 90% of this year’s tax or 100% of last year’s total tax — 110% if last year’s AGI was over $150,000. Enter last year’s tax to see that minimum. You’ll still owe any balance when you file, but without a penalty.

Want to see only the Social Security and Medicare part? Use the Self-Employment Tax Calculator. To bill clients professionally, try the free invoice generator.