Plain numbers, no upsell.

How we work.

Every calculator on this site is hand-built against the IRS's published rate schedule for the current tax year. The federal self-employment tax is 15.3% (12.4% Social Security + 2.9% Medicare) on 92.35% of net earnings — that's the IRS's standard Schedule SE adjustment, not a guess. State filing fees are pulled from each Secretary of State's published schedule and refreshed quarterly.

We are not a CPA firm and we do not provide tax advice. If you have a complex situation — multi-state operations, reasonable-comp disputes, inventory accounting, or anything involving more than one owner — hire a licensed CPA or EA. We give you the model so the conversation with that professional is shorter and cheaper.

Methodology & sources.

Tax year modeled: 2026. Federal assumptions are based on IRS Schedule SE (self-employment tax), IRS Topic No. 751 (FICA rates), IRS Publication 15 (employer FICA), IRS Form 8959 (Additional Medicare Tax), and IRS Form 2553 (S-Corp election). The Social Security wage base is published by the Social Security Administration each October for the following calendar year.

State filing fees and annual franchise / report fees are sourced from each state's Secretary of State (or equivalent) published fee schedule. The state income-tax flag reflects whether the state assesses an individual state-level income tax on pass-through business income; it is not a calculation. Income tax itself is not modeled.

What this calculator actually computes.

BizTaxMetrics estimates the federal payroll / self-employment tax difference between a U.S. Single-Member LLC using the default Schedule C treatment and the same business after an S-Corporation election. The calculator doesnot estimate your complete tax liability, and it doesnot claim to. It shows the three components of the difference — the federal payroll/SE tax delta, the state's recurring entity cost, and the modeled S-Corp admin overhead — separately so you can see where the final number comes from and change any of the inputs.

1. LLC — Self-Employment Tax (Schedule SE)

A default-taxed Single-Member LLC pays self-employment tax on its net earnings via IRS Schedule SE. The engine applies the standard 92.35% factor, splits the result into the Social Security portion (capped at the SSA wage base), the Medicare portion (uncapped), and the 0.9% Additional Medicare Tax above the filing-status threshold:

// LLC — self-employment tax (Schedule SE)
seBase          = netProfit × 0.9235              // 92.35% Schedule SE factor
ssPortion       = min(seBase, 184,500) × 12.4%   // Social Security, capped at SSA wage base
medicarePortion = seBase × 2.9%                                       // Medicare, no cap
addlMedicare    = max(0, seBase + existingWages − threshold) × 0.9%   // Form 8959, employee-side only
seTax           = ssPortion + medicarePortion + addlMedicare

// Thresholds: 200,000 (single) · 250,000 (marriedFilingJointly) · 125,000 (marriedFilingSeparately) · 200,000 (headOfHousehold)

Combined Social Security + Medicare = 15.3% on the 92.35% Schedule SE base. The 0.9% Additional Medicare Tax is entirely owner-side — there is no employer equivalent. The Social Security portion of SE tax is capped at the $184,500 wage base; above that, only Medicare (and Additional Medicare Tax, if applicable) continues to apply.

2. S-Corp — Payroll Tax (FICA on the Owner's W-2)

An S-Corp pays its owner-employee a W-2 salary. That salary is subject to FICA, with the employee half withheld and the employer half paid by the S-Corp. The remaining profit (the "distribution") isnot subject to SE/FICA — it still flows through to the owner's individual federal (and state) income tax return, but no payroll tax applies. The engine computes it like this:

// S-Corp — payroll tax on the owner's W-2
salary         = ownerSalary                                         // user-entered
distribution   = max(0, netProfit − salary)                          // not subject to SE/FICA

ssPortion      = min(salary, 184,500) × 12.4%   // SS, capped
medicarePortion = salary × 2.9%                                       // Medicare, no cap
standardFica   = ssPortion + medicarePortion
addlMedicare   = max(0, salary + existingWages − threshold) × 0.9%   // Form 8959, ENTIRELY employee-side

// IMPORTANT: 0.9% Additional Medicare Tax has no employer match.
employerFica   = standardFica / 2       // only the standard 15.3% FICA is split 50/50
employeeFica   = standardFica / 2 + addlMedicare
totalFica      = employerFica + employeeFica

The engine compares the LLC's full self-employment tax to the S-Corp's employer-side FICA only. Why? Because the employee's half of standard FICA would be owed on the salary either way (LLC or S-Corp) — only the employer half is actually different between the two structures, and that is the piece the S-Corp election removes. The 0.9% Additional Medicare Tax has no employer match; the S-Corp does not pay any portion of it. The owner pays the full 0.9% via W-2 withholding and/or Form 8959.

3. S-Corp administration overhead

An S-Corp generally involves more administration than a default Schedule C LLC, including:

• · A separate corporate tax return (Form 1120-S).
• · Setting up a payroll account and running payroll on the W-2 salary.
• · Quarterly and annual payroll filings (Form 941, Form 940, state withholding).
• · A payroll service (Gusto, ADP, Paychex, etc.) or in-house payroll software.
• · Ongoing bookkeeping for a corporate entity rather than a sole proprietorship.
• · Additional tax-preparation work — corporate return + personal return.

The calculator surfaces this as a configurable illustrative assumption, defaulted to $1,200/yr. The slider is exposed in the calculator UI so you can change it to match your actual expected cost. The default of $1,200 is meant to be a reasonable mid-market estimate; real costs vary materially based on your payroll provider, your CPA, and your state.

The $1,200 S-Corp administration overhead is anillustrative assumption, not a tax and not an IRS-required amount. It is not a fee collected by any government. It is a modeling choice to help you account for the real-world cost of running a corporate entity. The calculator labels it as such in every breakdown.

What isn't modeled.

This calculator is intentionally narrow. It models the federal payroll/SE tax difference between two structures, plus each state's recurring entity fee, plus a configurable admin overhead. It doesnot model any of the following — and the omission can materially change your real-world bottom line. Run the numbers, then verify with a CPA, EA, or tax attorney before deciding.

• · Federal individual income tax. The model shows payroll/SE tax only. Ordinary federal income tax (10%–37% brackets) applies to the same net earnings in both structures and is not calculated.
• · State individual income tax (dollar amounts). The site flags whether each state assesses one; it does not compute the dollar amount, because that depends on the owner's full return (filing status, spouse income, deductions, credits, residency, etc.).
• · Qualified Business Income (QBI) deduction under §199A. QBI can reduce the effective pass-through tax rate, and it interacts with the S-Corp's W-2 salary in ways the calculator does not capture.
• · Self-employed health insurance deduction (Schedule 1, line 17). The deduction is capped by net SE earnings / W-2 wages, so the same dollar of premiums can be more or less valuable depending on the structure.
• · Half-of-SE-tax Schedule 1 adjustment. An LLC owner can deduct one-half of their SE tax as an above-the-line adjustment. This reduces the effective cost of SE tax on a marginal-income basis, which the calculator does not net out.
• · Retirement-plan contributions (SEP-IRA, Solo 401(k), SIMPLE IRA). Contribution limits differ between an LLC and an S-Corp owner, and the difference is not modeled.
• · Filing-status-specific deductions and credits (child tax credit, education credits, EITC, itemized vs. standard deduction, etc.). These depend on the owner's full return and can swing the real-world answer.
• · Reasonable-compensation enforcement. The IRS does not publish a formula for "reasonable compensation." The calculator shows a soft warning when the salary is below 30% of net profit, but that is a UI hint, not a legal rule.
• · Multi-state operations or apportionment. If the business has nexus in more than one state, the state-fee line and the state-income-tax flag are not accurate.
• · Inventory, cost of goods sold, Section 199A specifics, or any item that depends on the user's full Schedule C / K-1 picture.
• · The LLC formation filing fee. Each state's one-time LLC formation fee is shown in the state-facts grid but is not deducted from the year-1 net benefit (it's a one-time setup cost, not a recurring annual cost).

What "estimated net modeled benefit" means here.

The big number the calculator displays is built up from three independent pieces, in this order:

1. 1. Federal payroll / SE tax difference.LLC self-employment tax minus the S-Corp's employer-side FICA on the owner salary. This is the federal payroll-tax piece only.
2. 2. Less the state's recurring annual fee.The state's modeled annual franchise / report / maintenance fee, where applicable. (Some states are $0; see the per-state page.)
3. 3. Less the modeled S-Corp admin overhead.The configurable bookkeeping + payroll + extra tax-prep assumption (default $1,200/yr).
4. = Estimated net modeled benefit.

This is the net modeled benefit in this calculator, not total tax savings. It does not include federal income tax, state income tax, the QBI deduction, the self-employed health insurance deduction, the half-of-SE-tax adjustment, retirement contributions, or any other item listed in "What isn't modeled" above. To get a real answer for your situation, take this number to a licensed CPA or EA and have them run the full Schedule C / Form 1120-S / Form 1040.

State-specific caveats.

State filing fees and annual franchise / report fees are pulled from each state's Secretary of State (or equivalent) published schedule. Where a state charges a minimum statutory fee (e.g. California's $800 minimum), the calculator uses the published minimum as a floor. Where a fee depends on capitalization, revenue, or other factors, the per-state page's notes field documents it.

Actual state-level costs are sometimes higher than the modeled figure. Two important cases the calculator explicitly flags:

• California. California imposes an $800 minimum annual franchise tax on EVERY LLC (RTC § 17941) AND, in addition, a tiered LLC fee under RTC § 17942 keyed to CA-source income: $0 below $250K, +$900 at $250K–$499,999, +$2,500 at $500K–$999,999, +$6,000 at $1M–$4,999,999, +$11,790 at ≥$5M. The total is $800 + surcharge (e.g., $1,700 at $300K CA-source income, $12,590 at $5M+). Net profit is used as a conservative proxy for CA-source income; actual surcharge depends on CA allocation factor, which this calculator does not compute. The $20 LLC Statement of Information is NOT modeled.
• New York. NY requires a $9 biennial statement (~$4.50/yr). NY LLCs formed in NY must also satisfy a county-level publication requirement within 120 days of formation (NY LLC Law § 206), which can cost $200–$2,000 depending on the county, plus a $50 Affidavit of Publication filing. This publication cost is a ONE-TIME first-year cost and is NOT included in the modeled annual fee or first-year filing cost.
• Massachusetts. MA has a higher-than-typical $500 LLC filing fee and a $500 annual report fee. At low net-profit levels, the S-Corp election in MA is often negative.
• Texas. Texas has no state individual income tax and no annual franchise tax for most LLCs (the Texas franchise tax only applies to entities with annualized revenue over $2.65M). The calculator shows $0/yr for the typical small-business case.
• Tennessee. The $300 minimum franchise tax is required for LLCs with taxable net worth over $1M; smaller LLCs may pay a reduced $100 fee. The calculator uses the $300 figure as a conservative default.

State income tax is not calculated as a dollar amount in this model. For the states that assess one, the per-state page shows a "Yes" flag — you should independently estimate your state income tax liability (or have a CPA do it) and add it to the calculator's net benefit to get a fuller picture.

Sources.

Federal figures are taken directly from the official sources below. State fees are sourced from each state's Secretary of State (or equivalent) — the per-state page shows the specific URL for each state.

• IRS — Self-Employment Tax (Social Security and Medicare Taxes) / Schedule SE
• IRS Topic No. 751 — Social Security and Medicare Withholding Rates
• IRS Publication 15 — Employer's Tax Guide (FICA rates)
• Social Security Administration — Contribution and Benefit Base ($184,500 for 2026)
• IRS — Additional Medicare Tax (Questions and Answers)
• IRS — S Corporation Compensation and Medical Insurance Issues (Reasonable Compensation)

How confident should I be?

• · Federal figures are computed from the IRS formulas above, applied to the inputs you provide. Within the limits of those formulas and inputs, they match what the IRS would compute for the same numbers.
• · The 2026 Social Security wage base is $184,500 (announced by the SSA in October 2025 for tax year 2026). It is the official figure, not a projection.
• · State fees are pulled from each Secretary of State's published schedule, with a minimum statutory floor applied where the state has one (e.g. California's $800 floor). Actual state-level costs can be higher in specific cases — see the state-specific caveats above.
• · The "reasonable compensation" warning in the calculator is a UI hint, not a legal rule. The IRS does not publish a hard threshold.
• · The 1,200 S-Corp admin overhead is a modeling default. Adjust it in the calculator to match your real expected cost.
• · For any consequential decision (electing S-Corp status, setting your salary, choosing a state), verify the final answer with a licensed CPA, EA, or tax attorney who can see your full return.

BizTaxMetrics is not a CPA firm and does not provide professional tax advice. The calculator is an editorial tool, not a substitute for one.

Methodology reviewed by [Pending CPA / EA] · pending engagement

Worked example: a $150K consultant in Texas.

To make the formula concrete, here is a single-owner Texas consultant with $150,000 net profit paying herself a $60,000 W-2 salary, $0 in other wages, and the default $1,200/yr admin overhead. Texas has no individual income tax and no LLC annual fee modeled, so the state-fee line is $0. You can reproduce every number in the homepage calculator.

The same inputs against a state with a fee (e.g. New York, where the S-Corp Article 9-A FDM tiers add cost) would reduce the modeled benefit by that fee. The methodology above remains identical; only the state-fee line changes.

What we don't do.

• · We don't sell tax preparation services.
• · We don't collect your data — there is no account, no form, no CRM.
• · We don't publish "sponsored" content or paid state rankings.
• · We don't claim CPA review unless an actual CPA reviewed a specific section.

Who we are.

BizTaxMetrics is an independent, owner-operated calculator and research project. There is no agency behind it, no paying clients, no sponsored placements, and nobody pays to be ranked in a state table. The project exists because we needed this comparison ourselves: we built the calculators we wished we had when we sat on the other side of the desk, instead of another “tax savings kit” sold at a fixed price.

The work is narrow on purpose. We model one decision — default LLC treatment versus an S-Corp election — and the recurring state cost of maintaining each entity. That means every figure on the site is traceable to a published source: the IRS rate schedules and forms (Schedule SE, Publication 15, Form 8959, Form 2553), the Social Security Administration’s wage base announcement, and each Secretary of State’s fee schedule. When a number moves, we log it on the updates page with an effective date and a link to the primary document, so you can see exactly when a figure entered the calculator and why.

We are deliberately not a professional services firm. No one on the team is a licensed CPA, enrolled agent, or tax attorney, we take no client engagements, and nothing here is advice about your specific return. What we do instead is make the math inspectable: the calculator exposes its assumptions, the methodology section spells out what is modeled and what is not, and every state page carries the date its fees were last checked against the official schedule. If a licensed professional reviews and signs off on a section in the future, we will say so on that section — and only then.

Corrections are part of the process rather than an exception. If you find a stale figure, a bad citation, or a calculation that does not reproduce, send it through the contact page with the source and we will update the page and log the change in the version history below.

Editorial team & review process.

BizTaxMetrics is an independent editorial project. The federal figures on this site are reviewed against IRS published sources (Schedule SE, Topic No. 751, Publication 15, Form 8959, Form 2553, and the SSA Contribution and Benefit Base announcement). State filing fees and annual franchise / report fees are reviewed quarterly against each Secretary of State's published fee schedule.

When to hire a professional instead.

This site models one thing: the federal payroll / self-employment tax difference between an LLC (default Schedule C treatment) and an S-Corp election, plus each state's recurring entity fee. It does not, and cannot, model your full tax situation. You should hire a licensed CPA, EA, or tax attorney if any of the following apply:

• · You operate in more than one state or have nexus in another state.
• · Your business holds inventory, cost of goods sold, or §199A-specified services (SSTBs).
• · You have multiple owners with non-pro-rata profit allocations.
• · You are considering a C-Corp election, a §1202 QSBS strategy, or a §174 R&D capitalization claim.
• · The IRS has previously audited your business or flagged a reasonable-compensation issue.
• · You are forming a new entity and need state-specific legal advice on operating agreements, buy-sell terms, or governance.

BizTaxMetrics is the conversation-shortener before that conversation: the calculator gives you a defensible starting number, the methodology page explains the assumptions, and the per-state page surfaces the fees. The rest is a professional's job.

Corrections & contact.

We treat factual errors as bugs and fix them fast. The fastest way to reach us is[email protected]with the citation link to the Secretary of State fee schedule (for state fee corrections) or the IRS source (for federal formula corrections). We answer most messages within two business days.

For partnership, press, or content corrections, see thecontact page.