Quick SE Tax
Quick Quarterly Payment
Quick QBI Savings
Formation — Scripture-Grounded Bible Study
Ask the Word, cross-referenced study tools, and reading plans that go deeper than a Sunday sermon. Free to start.
Try Formation Free →All Calculators
SE Tax Calculator
Full breakdown: 92.35% adjustment, Social Security wage base cap, and Medicare tax — now with a W-2 wages field that correctly reduces the remaining Social Security wage base.
Open Calculator →Quarterly Estimated Tax
Project your annual tax and split it into 4 quarterly payments with IRS deadlines and the safe-harbor rule explained.
Open Calculator →Additional Medicare Tax
Check if you owe the extra 0.9% Medicare tax based on your filing status and income.
Open Calculator →Deduction & QBI Savings
See how much the half-SE-tax deduction and 20% QBI deduction save you.
Open Calculator →How These Calculators Work
Every formula on this site is built directly from published federal rules — not estimates pulled from memory. Self-employment tax is 15.3% (12.4% Social Security + 2.9% Medicare) applied to 92.35% of net self-employment earnings, a stable statutory structure. The Social Security portion is capped at an annual wage base that the Social Security Administration updates periodically; the Medicare portion is not capped. These are federal-only estimates — they don't include state tax, credits, or every deduction or business-entity scenario, and none of them constitute personalized tax advice. See our full methodology on the About page and the Disclaimer for what each calculator does and doesn't cover.
From the Blog
How Self-Employment Tax Actually Works
A plain-English walk through the 92.35% adjustment, the Social Security cap, and the Medicare layer.
Read More →Quarterly Estimated Taxes: A Complete Guide
Deadlines, penalties, the safe-harbor rule, and how to handle uneven income.
Read More →What Is the QBI Deduction?
Who qualifies, the SSTB wrinkle, and why it only reduces income tax, not SE tax.
Read More →