Amara nets about $130,000 a year as an independent UX consultant. A free online calculator that only compares payroll taxes told her electing S-Corp status with a $70,000 salary would save her $7,658 a year. Running the same numbers through a calculation that also counts the QBI deduction she'd lose and the actual cost of running payroll puts her real savings at $2,213 — a fraction of what she was quoted, though still enough to make the election worthwhile.
What the Payroll-Tax-Only Number Gets Right (and Leaves Out)
The $7,658 figure isn't fabricated — it's a real comparison of self-employment tax against S-Corp payroll tax, and the mechanics are correct as far as they go. The problem is what most free calculators stop there, when two more real costs sit on the other side of the ledger: the cash cost of running payroll and a CPA-prepared S-Corp return, and a tax effect that's easy to miss entirely — S-Corp salary isn't eligible for the 20% Qualified Business Income deduction the way sole-proprietor profit is.
Step 1: The Payroll Tax Comparison (What Most Calculators Show)
As a sole proprietor, self-employment tax applies to 92.35% of net profit — the factor exists to approximate the "employer half" that a W-2 employee's wages never see taxed the same way twice:
$130,000 × 92.35% = $120,055 in net earnings, taxed at 15.3% (12.4% Social Security up to the wage base, plus 2.9% Medicare) = $18,368 in self-employment tax.
As an S-Corp paying herself a $70,000 salary, payroll tax (employee and employer share combined) applies only to that salary, not the full profit:
$70,000 × 15.3% = $10,710 in combined payroll tax.
Gross payroll-tax saving: $18,368 − $10,710 = $7,658. This is the number most free tools report as "your S-Corp savings" — and it's real, as far as it goes.
Step 2: What Running an S-Corp Actually Costs
Electing S-Corp status isn't free to administer. Realistic annual costs:
- Payroll software/service to actually run the $70,000 salary through payroll: $600/year
- The premium a CPA charges for an S-Corp return (Form 1120-S) over a simpler Schedule C: $1,800/year (varies by whether you already have CPA help)
Total compliance cost: $2,400/year, straight off the top of the $7,658 gross saving.
Step 3: The Deduction Amara Would Lose (The Part Most Calculators Skip)
This is the piece that changes the answer most. Wages are not Qualified Business Income — electing S-Corp status converts $70,000 of what would have been QBI-eligible profit into W-2 salary, and the 20% deduction on that slice disappears.
As a sole proprietor, after deducting half her SE tax and the standard deduction, Amara's QBI deduction comes to $20,943 (capped at 20% of her taxable income before the deduction, which binds below the $203,000 phase-out threshold).
As an S-Corp, only her $54,645 distribution (profit after salary and the company's employer-side payroll tax cost) is QBI-eligible. Her QBI deduction drops to $10,929 — less than half.
That $10,014 smaller deduction means more income gets taxed at ordinary rates: Amara's income tax as an S-Corp comes to $16,188, versus $13,142 as a sole proprietor — an extra $3,046 in income tax that a payroll-tax-only comparison never sees, because it never touches income tax at all.
The Real Number
| Amount | |
|---|---|
| Gross payroll tax saving | $7,658 |
| − Compliance costs (payroll + CPA) | −$2,400 |
| − Extra income tax from lost QBI | −$3,046 |
| Net savings | $2,213 |
$2,213 is still a real, positive number — the election is still worth it at Amara's income and salary level, just not by the margin she was originally quoted. The gap between $7,658 and $2,213 is $5,445, meaning the payroll-tax-only calculator overstated her actual benefit by roughly 246%.
Why This Isn't a Rounding Error
The QBI cost scales with income and salary choice in a way that can flip the answer entirely at different numbers — a consultant with a higher "reasonable salary" relative to profit loses proportionally more QBI room, and at the wrong combination, a payroll-tax-only calculator can show a healthy saving while the real number is negative. Amara's $2,213 sits close enough to the calculator's own break-even zone ($2,000) that a slightly higher CPA fee or a slightly different salary choice could tip it either way — which is exactly why the full calculation, not just the payroll-tax piece, is the one worth trusting before filing Form 2553.
What This Doesn't Include
This is federal tax only, assumes a single filer, and doesn't model any state-level S-Corp tax or fee — some states (California charges 1.5% of profit with an $800 minimum) impose a real, separate cost that would reduce net savings further. It also doesn't model the "reasonable salary" question itself: the IRS requires an S-Corp owner's salary to reflect fair market value for the work performed, and $70,000 has to be defensible on its own terms, not chosen just to optimize this comparison.
Run Your Own Numbers
Amara's $2,213 depends entirely on her specific profit and salary combination — a different salary choice, a lower CPA cost, or a higher income can move the answer meaningfully. Run your own net income and planned salary through the LLC vs S-Corp Tax Savings Calculator to see the full picture, not just the payroll-tax slice of it.
Frequently Asked Questions
Why did the QBI deduction cost Amara more than $10,000 instead of just 20% of her $70,000 salary?
Because QBI is calculated on taxable income after other deductions, not on raw profit or salary — and it's capped at 20% of that taxable income figure when that cap is lower than 20% of business income, which is the common case for a sole proprietor. The $10,014 gap is the difference between what 20% of her (larger) sole-proprietor taxable base allows versus 20% of her (smaller, salary-reduced) S-Corp distribution base — not a simple 20%-of-salary calculation.
Would a higher salary make the S-Corp election better or worse?
Both effects at once, in opposite directions. A higher salary means more payroll tax paid on a bigger slice (worse for the gross saving) but leaves a smaller distribution, which is already a shrunken QBI base — so the QBI cost changes too, in a way that isn't simply linear. This is exactly why "reasonable salary" isn't just a compliance checkbox — it's the single input that moves this entire calculation the most.
Is $2,213 in savings even worth the hassle of running an S-Corp?
That's a judgment call the calculator flags rather than answers — anything under $2,000 is treated as break-even territory where the administrative burden may not be worth it, and $2,213 is barely above that line. Someone who values simplicity highly, or who expects income to be volatile (S-Corp payroll can't easily flex down in a bad quarter the way sole-proprietor draws can), might reasonably decide the margin isn't worth the added complexity even though the math is technically positive.
Does this calculation change every year?
The dollar figures do — self-employment tax brackets, the Social Security wage base, and the QBI phase-out threshold all move with inflation adjustments most years, and CPA/payroll costs can change too. The mechanics (payroll tax comparison minus compliance costs minus lost QBI) stay the same; a decision made this year on this year's numbers should be re-run, not assumed to hold, if income changes materially.
Does electing S-Corp status cost anything at the state level beyond what's shown here?
It can, and this calculation only models it when specifically entered — a few states, California most notably, charge a real entity-level S-Corp tax (1.5% of profit with an $800 minimum for California) that isn't a personal income tax rate and doesn't cancel out the way state personal tax rates do on both sides of this comparison. Check your specific state's rules before assuming zero state-level cost.