Self-employed or freelancing? Estimate your federal income + self-employment tax and the quarterly payment to send the IRS so you avoid penalties. ✓ 2026 figures
1040-ES • Self-employed
If you're a freelancer, contractor, gig worker or small-business owner, the IRS expects tax payments four times a year rather than once. This calculator estimates your self-employment tax (15.3% on 92.35% of net profit) plus federal income tax (2026 brackets after the standard deduction and half-SE deduction), subtracts any withholding, and splits the rest into four equal payments.
Pay by the deadlines — Apr 15, Jun 15, Sep 15, and Jan 15 — and aim for the safe harbor (90% of this year's tax, or 100% of last year's, 110% if high income) to dodge the underpayment penalty. This is a simplified estimate excluding state tax, credits and deductions beyond the standard deduction. Not tax advice.
The US tax system is pay-as-you-go, so income without withholding — self-employment, investments, rental profit — requires quarterly estimated payments. Underpayment triggers a penalty computed as interest on each quarter's shortfall, so paying everything in April does not avoid it. The safe harbour rules are the practical shield: pay 100% of last year's total tax (110% if prior-year AGI exceeded $150,000) and you owe no penalty regardless of what this year turns out to be. That makes last year's return, not this year's forecast, the safest basis for setting the payments.
Quarterly payment = (Expected total tax − withholding) ÷ 4Safe harbour A: 90% of the current year's taxSafe harbour B: 100% of last year's tax (110% if prior AGI > $150,000)Due: 15 April, 15 June, 15 September, 15 Januarywhere:
Assumptions: Withholding is uniquely useful because it is deemed paid evenly across the year — increasing W-2 withholding late in the year can cure an earlier estimated-payment shortfall in a way an extra Q4 estimate cannot.
SourceIRS: estimated taxes
Compare a forecast-based payment with the safe harbour based on last year.
Result$4,350 a quarter under the safe harbour — $400 less than forecasting
The safe harbour is nearly always the better choice for variable income, because it fixes the required amount using a number you already know. Forecasting risks both overpaying (lending money to the IRS interest-free) and underpaying (a penalty), while the safe harbour risks neither.