LLC vs S Corp Tax Savings Calculator

LLC vs S Corp Tax Guide

What should I know about The Self-Employment Tax Problem?

Sole proprietors and single-member LLCs pay 15.3% self-employment tax on ALL net business income (up to Social Security wage base $176,100 in 2025, then 2.9% Medicare with no cap, plus 0.9% additional Medicare over $200k single/$250k MFJ). This is on TOP of federal and state income tax. A freelancer netting $120,000 pays roughly $16,950 in SE tax alone — before any income tax. S Corp taxation solves this by treating only your 'reasonable salary' as employment income (subject to FICA), with the remaining profit distributed free of self-employment tax.

What should I know about The Reasonable Salary Requirement?

IRS requires S Corp owner-employees to take a 'reasonable salary' — what you'd pay someone else to do your work. Set salary too low and the IRS will reclassify distributions as wages, owing back taxes, penalties, interest. Guidelines: industry benchmarks (BLS occupational data), local market rates, your specific role (CEO of one-person consultancy is different from rank-and-file work). Common ratios: 40-60% of net business income as salary for service businesses; 30-50% for product/sales businesses, as a rough starting point before consulting an accountant.

When S Corp Election Makes Sense?

Generally worthwhile above $50,000-70,000 net business income. Quick math: $120k net income, $70k reasonable salary. SE tax as sole prop: $120,000 × 0.9235 × 0.153 = $16,952. As S Corp: $70,000 × 0.0765 (employee FICA) + $70,000 × 0.0765 (employer FICA) = $10,710. SE tax saving: $6,242/year. Subtract compliance costs (~$2,000 = payroll service $800 + extra tax prep $1,200) = net saving $4,242/year. Stack annually = compound savings. Below $50k income, compliance costs eat the savings. Above $200,000 in profit, the savings typically become substantial enough that S Corp election is worth serious consideration for most self-employed business owners.

What do I need to know about S Corp Compliance Burden (the Costs)?

Electing S Corp adds real overhead: (1) Form 2553 election (one-time, before March 15 of effective year). (2) Quarterly payroll filings — federal 941, state withholding, unemployment. Must use payroll service (Gusto, ADP, OnPay $40-100/month) — DIY is risky. (3) Form W-2 issued to yourself annually. (4) Form 1120-S corporate tax return separate from personal — typically $800-2,000 from CPA. (5) State filings — some states (CA, NY, IL) have S Corp surcharges. California is a particularly costly example: an $800 annual franchise tax applies regardless of profit, which can significantly erode the tax savings for smaller S Corps based there. The formal election paperwork, operating agreement, and ongoing compliance documents can be prepared through services like LawDepot, which offers state-specific US business formation and compliance templates.

Why the Comparison Usually Comes Down to Self-Employment Tax

A default single-member LLC's profits pass through to the owner's personal tax return and are subject to self-employment tax (15.3% covering Social Security and Medicare) on the entire net profit. Electing S-corp tax treatment lets the owner split their income into a "reasonable salary" (subject to payroll taxes, which functionally mirror self-employment tax) and remaining profit distributions, which are not subject to self-employment tax or payroll tax at all. The potential saving is real, but entirely dependent on the gap between total profit and the salary the IRS would consider "reasonable" for the work performed — the larger that gap, the larger the potential saving, which is why S-corp election tends to pay off mainly once profits comfortably exceed a reasonable salary level, not for a business just breaking even.

The Hidden Costs That Can Offset the S-Corp Tax Saving

Electing S-corp status isn't free: it generally requires running formal payroll for the owner-employee's salary (with associated payroll processing costs and employer-side tax filings), typically a separate business tax return, and more rigorous bookkeeping to defend the "reasonable salary" figure if ever questioned by the IRS. These added administrative and accounting costs commonly run to a meaningful sum every year, which needs to be weighed against the projected self-employment tax saving — for a smaller business, the extra compliance cost can eat up most or all of the theoretical tax benefit, which is exactly the trade-off this calculator is built to quantify rather than assume automatically favors the S-corp.

How State-Level Taxes and Franchise Fees Change the LLC vs S-Corp Decision

The federal self-employment tax savings from electing S-corp status are only one side of the comparison, because state-level taxes and fees on each entity type vary substantially and can erode or even reverse the federal benefit. Some states impose an annual franchise tax or minimum fee simply for being a registered LLC or corporation, regardless of profit, which adds a fixed cost that a sole proprietor or simple single-member LLC taxed as a disregarded entity wouldn't face at all. A few states also levy their own tax on S-corp income or impose additional fees specifically tied to electing S-corp status, partially offsetting the federal self-employment tax saving that makes the election attractive in the first place. Payroll-related state taxes, such as state unemployment insurance, also apply once an owner starts taking a W-2 salary through an S-corp, adding a cost that doesn't exist for a sole proprietor paying themselves simply by withdrawing profit. Because these state-level costs vary so widely, the break-even profit level at which an S-corp election starts saving more than it costs in compliance and state fees can differ significantly from one state to another, even for two businesses with identical federal profit figures.

Reference: Self-Employment Tax Savings by Profit Level (Illustrative)

These figures are illustrative and depend heavily on the Social Security wage base (which changes yearly and caps the 12.4% Social Security portion), state tax treatment, and what the IRS would consider a defensible "reasonable salary" for the specific role and industry — the single biggest audit risk in an S-corp election is setting that salary too low relative to the work actually performed.

Worked Example: Where the S-Corp Saving Actually Comes From

A consultant nets $100,000 in profit after expenses. As a default single-member LLC (taxed as a sole proprietor), the entire $100,000 is subject to self-employment tax at roughly 15.3% up to the Social Security wage base, for SE tax of approximately $14,130 (after the standard adjustment that effectively taxes 92.35% of net earnings). Electing S-corp status and paying a reasonable salary of $55,000, that salary alone is subject to payroll tax (split employer/employee, economically similar to SE tax) of roughly 15.3% = $8,415. The remaining $45,000 is taken as a distribution, which is not subject to Social Security or Medicare tax at all — only income tax. Saving = $14,130 - $8,415 = approximately $5,715 before accounting for the extra costs of running payroll and filing a separate corporate return (payroll service, a business tax return, often $1,500-$3,000 a year combined). Net benefit in this example is therefore closer to $3,000-$4,000 — real money, but the gross headline saving overstates what actually reaches the owner's pocket, which is why the compliance cost line in the S-corp comparison matters as much as the tax-rate line.

Why Timing the Election Matters (Form 2553 Deadlines)

Electing S-Corp tax treatment for an existing LLC generally requires filing Form 2553 with the IRS within a fairly tight window — typically within the first two and a half months of the tax year the election is meant to apply to, or shortly after forming the entity for a brand-new business. Miss that window and the election usually can't take effect until the following tax year, meaning a business that decides mid-year that S-Corp treatment would save money often has to wait, sometimes losing a full year of the available saving. Because of this, it's worth modelling the LLC vs S-Corp comparison well before year-end rather than waiting until tax season, since the decision window closes earlier than many self-employed business owners expect.

How Health Insurance and Retirement Contributions Are Treated Differently

A self-employed sole proprietor or single-member LLC owner typically deducts health insurance premiums and retirement contributions like a SEP-IRA or Solo 401(k) directly against their overall income. Under an S-Corp structure, a greater-than-2% shareholder-employee's health insurance premiums are usually added to their W-2 wages for income tax purposes (though still exempt from payroll tax in many cases) rather than deducted the same simple way, which adds a layer of payroll administration most owners don't anticipate. Retirement contributions under an S-Corp are generally based on the W-2 salary actually paid, not total profit, which means a very low salary deliberately kept down to minimise payroll tax also caps how much can be contributed to a retirement plan — one of several ways the salary decision ripples into other parts of the tax picture beyond the headline self-employment tax saving.