When you work as a W-2 employee, your employer withholds Social Security and Medicare taxes from every paycheck and then matches them on your behalf. When you are self-employed — a freelancer, independent contractor, gig worker, or sole proprietor filing Schedule C — there is no employer to do that. Instead, you pay the self-employment tax (SE tax) on Schedule SE of Form 1040, which covers both halves of those contributions. It is a separate tax from your federal income tax, and many new contractors are caught off guard by how large it is.
This calculator estimates your 2024 self-employment tax from your net business profit. It applies the official IRS formula — the 92.35% rule, the 12.4% Social Security portion capped by the annual wage base, and the 2.9% Medicare portion with no cap — then shows the half of the SE tax you can deduct above the line. Enter your net profit and every figure updates instantly.
How to Use
- Enter your Net Self-Employment Profit. This is your Schedule C bottom line: business revenue minus ordinary business expenses (supplies, mileage, home-office, software, contractors). Do not subtract your own "salary" — for a sole proprietor, everything left over is profit.
- Choose the Tax Year. The only number that changes between years is the Social Security wage base: $160,200 for 2023 and $168,600 for 2024. The 15.3% rate and the 92.35% rule stay the same.
- Pick your Filing Status. This sets the Additional Medicare Tax threshold on Form 8959: $200,000 for single and head of household, $250,000 for married filing jointly, and $125,000 for married filing separately. Above that threshold, a 0.9% surtax applies on top of the base 2.9% Medicare.
- Read the result card from top to bottom:
- Net Earnings (92.35%) — the taxable base for SE tax. The IRS lets you deduct the "employer-equivalent" share up front, so you pay SE tax on only 92.35% of your profit.
- Social Security Tax (12.4%) — only on net earnings up to the wage base.
- Medicare Tax (2.9%) — on all net earnings, with no upper cap.
- Base SE Tax (15.3%, Schedule SE) — the combined figure you report on Schedule SE.
- Additional Medicare Tax (0.9%, Form 8959) — the surtax on net earnings over your filing-status threshold, owed on Form 8959 (not Schedule SE).
- Total SE + Additional Medicare — everything self-employment-related you owe for the year.
- Deductible Half of SE Tax — 50% of the base SE tax, an above-the-line adjustment to income on Schedule 1.
Set aside roughly 25–30% of your profit for taxes (income tax plus SE tax combined). If you expect to owe $1,000 or more, the IRS requires quarterly estimated tax payments in April, June, September, and January.
The 15.3% Formula Explained
The SE tax rate is 15.3%, but it is applied in two pieces:
- 12.4% for Social Security — only on net earnings up to the annual wage base ($168,600 in 2024). Above that, no more Social Security tax is due for the year.
- 2.9% for Medicare — on all net earnings, no cap at all.
Crucially, you do not pay 15.3% on your full profit. The IRS multiplies your net profit by 0.9235 first. This treats you as your own employer: the employer's half (7.65%) is excluded from the taxable base. So the effective rate on profit is about 14.13% at lower incomes (because 0.9235 × 15.3% ≈ 14.13%), and it drops sharply once you cross the Social Security wage base, because only the 2.9% Medicare piece keeps growing.
Net earnings = net profit × 0.9235
SE tax = min(net earnings, wage base) × 12.4% + net earnings × 2.9%
And finally: the IRS lets you deduct half of the SE tax you owe. This is the "employer-equivalent" portion again, claimed as an adjustment to income — it lowers your adjusted gross income (AGI), though it does not reduce the SE tax itself.
Examples
Example 1 — A part-time freelancer. A designer nets $50,000 from contract work in 2024. Net earnings are $50,000 × 0.9235 = $46,175. Social Security tax is $46,175 × 12.4% = $5,725.70, and Medicare tax is $46,175 × 2.9% = $1,339.08. Total SE tax is $7,064.78, of which half — $3,532.39 — is deductible. The effective burden on profit is about 14.1%.
Example 2 — A six-figure contractor. A consultant nets $100,000. Net earnings are $92,350, well under the $168,600 wage base, so the full 15.3% applies. Social Security is $11,451.40, Medicare is $2,678.15, total SE tax is $14,129.55, and the deductible half is $7,064.77.
Example 3 — Crossing the wage base. An earner nets $1,000,000. Net earnings are $923,500, but Social Security tax stops at the wage base: $168,600 × 12.4% = $20,906.40. Medicare keeps running on the full $923,500: $26,781.50. Total SE tax is $47,687.90 — and notice the effective rate has fallen to under 5%, because the 12.4% Social Security piece capped out. The deductible half is $23,843.95.
FAQ
What is the self-employment tax rate for 2024?
The combined rate is 15.3%, made up of 12.4% for Social Security and 2.9% for Medicare. It applies to 92.35% of your net self-employment profit, not to the full amount. The 12.4% Social Security portion only reaches net earnings up to $168,600 in 2024; the 2.9% Medicare portion applies to all net earnings.
Who has to pay self-employment tax?
You owe SE tax if your net earnings from self-employment are $400 or more in a year. This includes freelancers, independent contractors, gig-economy drivers and delivery workers, small-business owners filing Schedule C, and members of a partnership. W-2 employees do not pay SE tax because their employer withholds and matches these taxes already.
Why do I pay SE tax on 92.35% and not 100% of my profit?
Because self-employed people act as both employee and employer. The IRS lets you deduct the hypothetical "employer's share" (7.65%) from the base before applying the tax. Mathematically, 100% − 7.65% = 92.35%, and that is why the multiplier is 0.9235.
How does the Social Security wage base work?
The 12.4% Social Security tax only applies to net earnings up to an annual cap — $168,600 in 2024 ($160,200 in 2023). Once your net earnings pass that threshold, you stop paying the 12.4% piece; the 2.9% Medicare tax keeps applying to every additional dollar. This is why the effective SE tax rate falls for very high earners.
Can I deduct half of the self-employment tax?
Yes. You may deduct 50% of the total SE tax as an above-the-line adjustment to income on Schedule 1 of Form 1040. This lowers your AGI, which can help with other income-based phase-outs, but it does not reduce the SE tax you actually owe — it only reduces your income tax base.
Is self-employment tax the same as federal income tax?
No. They are separate. SE tax funds Social Security and Medicare; federal income tax funds general government. You owe both on top of each other, which is why self-employed workers should set aside a combined 25–30% of profit and make quarterly estimated tax payments if they expect to owe $1,000 or more.
Do I owe SE tax if my business lost money this year?
No. If your net profit is zero or negative, your net earnings from self-employment are treated as zero, and you owe no SE tax for that year. A loss can also sometimes reduce your other income, but it does not generate a refundable SE tax credit.
Disclaimer
This self-employment tax calculator is provided for informational purposes only and does not constitute tax, legal, or financial advice. Figures are estimates based on the inputs you enter and the IRS Schedule SE and Form 8959 formulas for 2023–2024; they include the 15.3% base SE tax and the 0.9% Additional Medicare Tax on high earners, but exclude state taxes, itemized or above-the-line deductions beyond the SE-tax half, the QBI deduction, and your federal income tax. Actual liability depends on your full return, other W-2 wages, and current IRS guidance. Always confirm your final numbers with a qualified tax professional before filing or making estimated payments.