Self-employment tax comes first
It is charged on 92.35% of your net profit, and it starts from the first dollar — there is no allowance, no threshold, no gentle start. Social Security stops at the wage base; Medicare never stops.
Two deductions most advice forgets
Half your self-employment tax comes off your adjusted gross income, and the Section 199A pass-through deduction takes 20% of qualified business income. The usual "set aside 30%" rule ignores both and has you over-saving all year.
Four deadlines, not one
Estimated payments fall due in April, June, September and January. Penalties accrue for missing them even if you pay the full amount later.
Try it with your own figures
Show the working
What this does not cover. Twenty-four states are computed exactly — nine have no income tax and fifteen charge a single flat rate. The other twenty-six and the District of Columbia have graduated brackets this calculator does not model, so it asks you for a rate and says so rather than guessing.
Track it all year
The calculator answers today. The app remembers, watches every invoice, and in December tells you what you forgot to claim.
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