The 15.3% nobody warned you about
Employees pay 7.65% in FICA and never see the rest; the self-employed pay both halves. The 2026 self-employment tax is 12.4% Social Security on 92.35% of net profit up to the $184,500 wage base, plus 2.9% Medicare on all of it with no ceiling — an effective 15.3% on most freelance income before income tax even starts. High earners then add the 0.9% additional Medicare tax above $200,000 single / $250,000 joint. The 92.35% multiplier exists so that employees and the self-employed reach roughly the same taxable base; it is not a "discount," it is parity arithmetic.
The deduction that softens the blow
Half of your self-employment tax is an above-the-line deduction — you pay the full 15.3%, but taxable income shrinks by the employer-equivalent half. On $48,000 of profit: SE tax runs about $6,782, and $3,391 of it comes off taxable income before the brackets even begin. Stack the $16,100 standard deduction (single, 2026) and your taxable income on $48,000 of freelance profit is only about $28,500 — which is why the income-tax number on a 1099 is so much lower than newcomers expect. The income tax and the SE tax are separate computations, and the calculator shows both lines because conflating them is the classic freelance budgeting error.
What still counts as a business expense in 2026
The calculator asks for net profit, so your ordinary and necessary expenses — software, equipment, home office, professional services, health insurance premiums — should already be subtracted. Three 2026-specific notes: qualified tips paid in the course of the business follow the new $25,000 tips deduction rules; the QBI deduction generally removes up to 20% of qualified business income below the 2026 thresholds, which this estimator conservatively does not assume (many freelancers qualify — real software at filing time usually finds it); and the home office simplified method stays at $5 per square foot up to 300 square feet. When in doubt, categorize aggressively but honestly — expenses are the strongest lever a 1099 filer has.
A worked example: $48,000 freelance profit
Net profit $48,000 → SE base $44,328 → SE tax $6,782 (12.4% × $44,328 to the wage base + 2.9% Medicare). Half-SE deduction $3,391. Taxable income: $48,000 − $3,391 − $16,100 = $28,509 → through the 2026 single brackets: $12,400 at 10% + $16,109 at 12% ≈ $3,173 income tax. Total federal ≈ $9,955, an effective 20.7% on profit — versus the $2,200-a-year shock many first-timers predict when they hear "self-employment tax." Each quarter’s share is about $2,489, which the calculator rounds into the payment suggestion below the result.
Quarterly payments are the discipline that matters
The IRS expects taxes as you earn: April 15, June 15, September 15 and January 15 of the following year for 2026 income. Miss them and the underpayment penalty accrues per quarter at the federal short-term rate plus three points — not catastrophic, but pure waste. Two safe harbors keep you penalty-free: pay 90% of the current year’s tax, or 100% of last year’s (110% if prior-year income topped $150,000) via four equal estimates. New freelancers typically anchor to last year’s total, which works beautifully in a growth year — you underpay relative to reality with zero penalty, and the balance due at filing is interest-free. The quarterly calculator splits your projected annual number into the four dated payments.
Estimates for planning only — not tax, legal or accounting advice. Your actual return depends on facts this tool does not ask about. Figures are based on IRS Revenue Procedure 2025-32 (tax year 2026), verified October 2026.