Self-Employment Tax Calculator

What a self-employment tax calculator works out

A self-employment tax calculator works out the Social Security and Medicare tax a sole proprietor, freelancer or contractor owes on Schedule SE: 12.4 % Social Security on net earnings up to the wage base and 2.9 % Medicare on all of them, where net earnings are 92.35 % of net profit — plus the 0.9 % additional Medicare tax and the deductible half.

This page follows Schedule SE line by line for the tax year you pick and shows which lines your figures land on. It does not compute income tax on the profit — that is the income tax calculator — and it does not decide S-corporation questions or a "reasonable salary"; those are advice.

How much is self-employment tax on $75,000?

$10,597.16 for a single filer with no W-2 job in 2026. Net earnings are $75,000 × 0.9235 = $69,262.50; Social Security is 12.4 % of that, $8,588.55, because it is well inside the $184,500 wage base; Medicare is 2.9 %, $2,008.61. That is 14.1 % of net profit, not 15.3 %, and half of it — $5,298.58 — comes off adjusted gross income on Schedule 1. On $10,000 of side income the same arithmetic gives $1,412.96; on $200,000 it gives $28,234.30, because Social Security stops at the wage base and only Medicare continues on the last $200 of net earnings.

The quick rule of thumb is 14.13 % of net profit (0.9235 × 15.3 %) up to roughly $199,783 of profit — the point where net earnings reach the wage base — and 2.68 % (0.9235 × 2.9 %) of every dollar above it, plus 0.83 % (0.9235 × 0.9 %) once wages and net earnings pass $200,000 or $250,000.

What the 92.35 % factor on Schedule SE actually does

IRC §1402(a)(12) lets self-employed people deduct the equivalent of the employer half of FICA (7.65 %) before the tax is figured, which is why Schedule SE line 4a multiplies net profit by 92.35 %. Employees never pay tax on the half their employer contributes; the factor gives the self-employed the same footing. On $75,000 of profit it removes $5,737.50 from the base.

The deductible half (Schedule SE line 13, Schedule 1 line 15) is a different relief taken at a different stage: the 92.35 % shrinks the base the SE tax is computed on, and the half-deduction then shrinks the income your income tax is computed on. Neither reduces the SE tax after it is known.

Self-employed with a W-2 job: how the Social Security wage base offset works

Social Security tax stops at the wage base — $184,500 in 2026 — and Schedule SE line 8a subtracts the Social Security wages on your W-2 before testing your net earnings against it. An employee with $120,000 of wages and $100,000 of net side-business profit has $92,350 of net earnings but only $64,500 of wage base left, so Social Security is 12.4 % of $64,500 = $7,998, not 12.4 % of $92,350 = $11,451.40. Medicare is still 2.9 % of the full $92,350, $2,678.15, and because wages plus net earnings come to $212,350 the 0.9 % surcharge applies to $12,350: $111.15. SE tax $10,676.15; the one-input answer would have been $14,129.55.

When W-2 wages already reach the wage base, no Social Security is due on the side income at all: $50,000 of profit beside $184,500 of wages owes only Medicare, $1,339.08 (plus $276.08 of additional Medicare on the $30,675 of combined earnings above $200,000). Enter the Medicare wages from Box 5 of your W-2; the calculator caps the Social Security offset at the wage base itself and uses the whole figure for the 0.9 % test, which is what Forms 8959 and Schedule SE do.

Medicare has no wage base. It applies to every dollar of net earnings whatever your wages, which is why the two parts of SE tax are always computed separately.

The 0.9 % additional Medicare tax and married couples

Form 8959 adds 0.9 % on the amount by which Medicare wages plus SE net earnings exceed $200,000 (single, head of household) or $250,000 (married filing jointly). The thresholds are fixed in law and never indexed. For a couple the test is joint even though each spouse files their own Schedule SE: a spouse with $150,000 of W-2 wages and a spouse with $120,000 of net profit ($110,820 of net earnings) have $260,820 of combined earnings, $10,820 over the line, so the surcharge is $97.38 on top of $16,955.46 of SE tax.

The surcharge is the employee-side rate only — it is not doubled the way the 2.9 % is — and it is not part of the half-deduction. A self-employed single filer with $250,000 of profit owes $29,573.38 of SE tax plus $277.88 of additional Medicare on the $30,875 of net earnings above $200,000.

Quarterly estimated taxes for the self-employed and what is left out

If you expect to owe $1,000 or more after withholding, the IRS expects quarterly estimates on Form 1040-ES, due around April 15, June 15, September 15 and January 15 of the following year (the next business day when a date falls on a weekend or holiday). The payment covers income tax as well as SE tax, so the SE figure divided by four — about $2,649 a quarter on $75,000 of profit — is a floor, not the amount. To avoid an underpayment penalty, withholding plus estimates must reach 90 % of this year's total tax or 100 % of last year's (110 % if last year's AGI was above $150,000).

What this calculator does not model: the farm and non-farm optional methods (Schedule SE Part II), church employee income, ministers and members of religious orders, partnership guaranteed payments and K-1 self-employment earnings beyond a plain net-profit figure, state taxes, and the income tax on the profit. Net profit below $433.13 (net earnings below $400) is reported as income but owes no SE tax.