Choosing between taxation as a standard single-member LLC and electing S-Corporation tax status is one of the most critical structural decisions for growing service businesses and consultants. Under standard LLC pass-through taxation, 100 percent of net business profits are subject to the 15.3 percent self-employment tax (FICA). By electing S-Corp status (IRS Form 2553), business owners pay self-employment payroll taxes only on their reasonable W-2 officer salary, while remaining profit distributions bypass the 15.3 percent levy.

### Tax Mechanics and Comparative Formulations The calculator computes comparative tax obligations across both organizational models:

- **Standard LLC Self-Employment Tax:** $$\text{LLC Tax} = \text{Net Business Income} \times 0.153$$ - **S-Corporation Payroll FICA Tax:** $$\text{S-Corp Tax} = \text{Reasonable Owner Salary} \times 0.153$$ - **Gross Annual Self-Employment Tax Savings:** $$\text{Annual Savings} = \max(0, \text{LLC Tax} - \text{S-Corp Tax})$$

### Worked Numeric Example Evaluating the default calculator parameters: - **Net Annual Business Income:** $120,000 - **Reasonable Owner Salary:** $60,000 (W-2 wage compensation) - **Remaining Owner Distributions:** $60,000 ($120,000 - $60,000) - **Step-by-Step Calculation:** 1. Standard LLC tax liability: $120,000 \times 0.153 = \mathbf{$18,360}$. 2. S-Corp officer payroll tax: $60,000 \times 0.153 = \mathbf{$9,180}$. 3. Non-wage profit distributions: $60,000 \times 0\%\text{ SE tax} = $0. 4. Gross tax savings: $18,360 - $9,180 = \mathbf{$9,180 / year}$.

### Invoicing and Business Structuring Best Practices While saving $9,180 in payroll taxes is compelling, operating an S-Corporation introduces administrative compliance overhead. Running an S-Corp requires setting up formal payroll software ($500–$1,000/yr), filing quarterly payroll returns (Form 941), submitting an annual corporate tax return (Form 1120-S, typically $1,000–$2,000 in CPA fees), and paying state corporate franchise fees. As a guideline, electing S-Corp status becomes economically advantageous when sustained net profit exceeds $80,000 to $100,000 annually. All computations execute strictly inside your local browser sandbox; no income figures or corporate finances are uploaded or stored externally.