LLC vs Sole Proprietor — Methodology

Last updated: July 2025 · Tool: LLC vs Sole Proprietor Calculator

This tool calculates total tax liability under three business structures and shows the annual savings or costs of each. Here is exactly how each calculation works.

Structure 1: Sole Proprietor (and default LLC)

A sole proprietor and a single-member LLC with no tax election are treated identically by the IRS — both report income on Schedule C and pay self-employment tax on net profit. The calculation:

Net Profit = Gross Revenue − Business Expenses SE Tax Base = Net Profit × 0.9235 SE Tax = SE Tax Base × 0.153 SE Tax Deduction = SE Tax ÷ 2 (deductible from gross income) Taxable Income = Net Profit − SE Tax Deduction Federal Income Tax = Progressive brackets applied to Taxable Income State Income Tax = Taxable Income × State Rate Total Tax = SE Tax + Federal Income Tax + State Income Tax

Structure 2: LLC with S-Corporation election

Under S-Corp taxation, the owner splits income into two parts: a "reasonable salary" subject to payroll taxes, and distributions not subject to self-employment tax. This split is the source of potential tax savings.

Salary = User-entered reasonable salary (must be defensible as market rate) Distribution = Net Profit − Salary Payroll Tax on Salary = Salary × 0.153 (Both employee and employer sides, since owner pays both) Employer Payroll Tax = Salary × 0.0765 (Deductible as business expense) Taxable Income = Salary − Employer Payroll Tax + Distribution Federal Income Tax = Progressive brackets applied to Taxable Income State Income Tax = Taxable Income × State Rate Compliance Costs = $1,500 estimated (Payroll service ~$600/yr + additional accounting ~$900/yr above Schedule C) Total Cost = Payroll Tax + Federal Income Tax + State Income Tax + Compliance Costs

The S-Corp savings formula

The savings from S-Corp election comes entirely from avoiding SE tax on the distribution portion:

SE Tax Saved = Distribution × 0.9235 × 0.153 Net Annual Saving = SE Tax Saved − Compliance Costs Break-even occurs when SE Tax Saved > Compliance Costs At $1,500 compliance cost: Break-even ≈ $1,500 ÷ (0.9235 × 0.153) ≈ $10,625 in distributions Which means net profit needs to exceed salary + $10,625 to generate net savings In practice, the $60,000–$80,000 net profit threshold accounts for the need to pay a reasonable salary (~$50,000–$60,000) before meaningful distributions are possible.

Why the compliance cost is fixed at $1,500

We use $1,500 as a conservative estimate for the additional annual cost of S-Corp operation versus a simple Schedule C filing. This reflects: payroll service subscription ($400–$800/year for services like Gusto or ADP), additional CPA time to prepare Form 1120-S and review quarterly payroll filings ($700–$1,500/year above Schedule C cost), and estimated state-specific fees where applicable. In practice, costs range from $1,000 to $3,000+ depending on location and accountant. The $1,500 figure is intentionally conservative — it makes the tool more likely to recommend S-Corp only when savings are clear.

Limitation: This calculator does not account for California's $800 minimum franchise tax on LLCs, state-specific LLC gross receipts fees, or local business taxes. California-based users should add those costs to the LLC total before comparing. The tool also uses simplified federal tax brackets without itemized deductions — actual results will vary based on individual tax situations.

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Enter your revenue and get a side-by-side tax comparison across all three structures.

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