Quarterly Estimated Tax Calculator

Calculate quarterly estimated tax payments for freelancers and self-employed individuals. Includes both income tax and self-employment tax (15.3%).

This calculator combines federal income tax and self-employment tax into one quarterly payment estimate. Self-Employment Tax is 15.3% (12.4% Social Security, capped at the 2026 wage base of $184,500, plus 2.9% Medicare with no cap) applied to 92.35% of self-employment income (line 26-29), and half of that SE tax is then deducted from taxable income (line 30, 32), mirroring the real above-the-line SE tax deduction. Taxable income combines W-2/other income and self-employment income, minus deductions and the SE deduction, floored at zero (line 32), and computeFederalTax applies the 2026 brackets to that figure. Self-employment income moves the combined Total Tax Liability and Quarterly Payment more than an equal change to W-2 income does, since it feeds both the SE tax calculation directly and the income-tax base, while W-2 income only affects the income-tax side. Self-Employment Tax itself responds only to self-employment income; W-2 income and deductions have no effect on it at all, since Social Security and Medicare tax are computed purely from self-employment earnings. Filing status has the largest effect on Effective Tax Rate, since it selects an entirely different bracket table. Quarterly Payment is simply Total Tax Liability divided by four, assuming four equal installments; it does not account for the IRS's safe-harbor rules or any income earned unevenly across the year.