Quarterly Estimated Tax Calculator 2026 · US federal

Why freelancers owe more than they expect

An employee splits Social Security and Medicare with their employer. Self-employed people pay both halves — that's the 15.3% self-employment tax, and it applies on top of income tax, starting from the first dollar of profit rather than after the standard deduction. That's the single biggest reason a first tax bill as a freelancer feels so much larger than expected.

Three things soften it, and this calculator applies all three: only 92.35% of your profit is subject to SE tax, half of the SE tax you pay is deductible against your income tax, and most self-employed people can deduct another 20% of business income through the QBI deduction.

What "safe harbor" means

The IRS charges a penalty for underpaying during the year, but it gives you a guaranteed way out: pay either 90% of what you end up owing this year, or 100% of what you owed last year (110% if last year's AGI was over $150,000). Hit either and you owe no penalty, even if your final bill is much larger. For a freelancer with an unpredictable year, the prior-year route is usually the safer target — enter last year's numbers above to see it.

Due dates for 2026

April 15, June 15, and September 15 of 2026, then January 15 of 2027. They're not evenly spaced — the "second quarter" is only two months. If a date falls on a weekend or holiday it moves to the next business day; none of the 2026 dates do.

Honest limits of this tool

This is an estimator, not tax preparation, and it is not tax advice. It models the situation most freelancers are in — self-employment profit, standard deduction, maybe a spouse or a part-time job — and deliberately leaves out the long tail of credits, state taxes, and special cases. If your income is uneven across the year, the IRS annualized income installment method may let you pay less early on than the even split shown here.

Working backwards from this

If the tax bill above is bigger than the income you're actually clearing, the problem is usually the rate rather than the tax. The hourly rate calculator works the other way round: start from the take-home income you want and find the rate that gets you there once tax, expenses, and non-billable time are accounted for.

Read more

For the full picture — who has to pay, how the penalty is actually calculated, how to pay the IRS, and the mistakes that produce April surprises — see the guide on quarterly estimated taxes.

Where these figures come from

Brackets, the standard deduction, and the §199A thresholds are the 2026 amounts from IRS Rev. Proc. 2025-32; the $184,500 Social Security wage base is the SSA figure for 2026; due dates and safe harbor rules follow IRS guidance on estimated tax. They're kept in one file and updated when the IRS publishes each year's adjustments.