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Free 1099 Tax Tool

Self-Employment Tax Calculator

Enter your business profit and W-2 wages to estimate self-employment tax and simplified federal income tax. Review withholding, credits, prior payments, and safe-harbor rules before deciding what to pay.

Your Numbers

Self-employment tax$16,955

Example figures, replace with yours

$

Revenue minus business expenses.

$

Day-job wages count against the Social Security cap first.

Filing Status

Federal only, using the 2026 standard deduction, official 2026 brackets, and a simplified QBI computation (SSTB and wage limits not modeled). State income tax not included.

Self-employment tax, 2026 figures

$16,955

Modeled federal income tax: $11,506

Modeled income tax plus SE tax: $28,462 (23.7% effective)

Illustrative and federal only, not a recommended payment; the estimated tax penalty calculator shows what a missed installment costs.

Next estimated payment (safe harbor)

$24,000

due January 15, 2027

Smaller of the prior-year and current-year methods, minus what you have paid. Estimate, not a recommended payment. Change last year's tax and payments

Paying five figures in SE tax?

Book your free 30-minute tax fit call to talk through your next steps.

Tax planning slots are limited before year-end.

An entity decision depends on reasonable compensation, payroll and filing costs, operating states, and your existing wages. See how our CPA for self-employed service works.

Run the S-Corp Numbers
See the line-by-line breakdown

Self-Employment Tax

Social Security (12.4%)$13,742
Medicare (2.9%)$3,214
Total SE Tax$16,955

Federal Income Tax

Half-SE-tax deduction−$8,478
QBI deduction (est.)−$19,084
Taxable income$76,338
Income Tax$11,506

Quarterly tax calculator for 1099 income

The IRS does not ask what you earned this quarter. It asks whether your payments to date reach the required annual payment. Enter last year's total tax and what you have paid so far; the calculator shows the smaller of the two safe harbors and what is left for the next due date.

$

The total tax line of your 2025 Form 1040, not the balance due.

$

Withheld and expected for the year from a W-2 job or other pay. It counts evenly toward each due date.

$

Federal estimated payments already made for 2026.

Next estimated payment (safe harbor)

$24,000

due January 15, 2027

Required for the year: $24,000 (100% of last year's tax).

The two safe harbors, the 110 percent rule for higher incomes and the due dates are explained on our estimated tax payments page, and the estimated tax penalty calculator shows what a missed installment costs.

If your income arrives unevenly, the annualized method on Form 2210 Schedule AI can lower early payments.

Quick Answer

Self-employment tax is 15.3% of 92.35% of your net 1099 profit. 12.4% Social Security (capped at the $184,500 wage base for 2026) plus 2.9% Medicare (uncapped), and it applies before any income tax. Two offsets soften it: half the SE tax is deductible, and most self-employed income qualifies for the 20% QBI deduction. This calculator models SE tax and simplified income tax, and its quarterly section applies the safe-harbor methods to last year's tax and the payments you have made.

Worked example

A single freelancer with $120,000 of net profit and no W-2 job

A single consultant nets $120,000 on Schedule C in 2026, has no W-2 wages, and takes the standard deduction. These are the calculator's own placeholder values.

Inputs

Worked example inputs
Net self-employment profit$120,000
W-2 wages$0
Filing statusSingle

Calculator output

Worked example calculator output
Net earnings subject to SE tax (92.35%)$110,820
Social Security (12.4%)$13,742
Medicare (2.9%)$3,214
Total SE tax$16,955
Half-SE-tax deduction$8,478
QBI deduction (estimate)$19,084
Taxable income$76,338
Federal income tax$11,506
Modeled federal tax (SE + income tax)$28,462 (23.7% of income)
Required for the year (100% of last year's tax)$24,000
First estimated payment, due April 15, 2026$6,000

SE tax is computed on 92.35% of profit, not the full $120,000. Half of the SE tax and the QBI deduction then reduce the income subject to income tax, but not the SE tax itself. With last year's tax at $24,000, 100% of it is smaller than 90% of this year's modeled tax ($25,616), so a quarter of it is the first payment. That is an estimate, not a recommended payment.

Methodology

How this calculator works

The calculator computes 2026 self-employment tax on your net profit, then a simplified federal income tax on the same profit plus any W-2 wages.

Formulas

  • Net earnings = net profit x 92.35%.
  • Social Security = 12.4% x the lesser of net earnings or ($184,500 minus W-2 wages); Medicare = 2.9% x net earnings.
  • Additional Medicare = 0.9% x (W-2 wages + net earnings) above $200,000 single or $250,000 married filing jointly.
  • Taxable income = profit + wages minus half of SE tax, minus the standard deduction, minus a QBI deduction of 20% x (profit minus half of SE tax), capped at 20% of taxable income.
  • Income tax uses the 2026 brackets; modeled tax = SE tax + income tax.
  • Required for the year = the smaller of 90% of modeled tax or last year's total tax (110% of it when last year's AGI was over $150,000); without last year's tax, 90% of modeled tax.
  • Next payment = (required for the year minus 2026 withholding) x installments due so far / 4, minus estimated payments made, never below zero. None is shown when modeled tax minus withholding is under $1,000.

Assumptions

  • Single or married filing jointly, standard deduction, no other income or adjustments.
  • The business is not limited by the QBI specified-service or W-2 wage rules at your income level.
  • Any W-2 wages you enter have already used part of the Social Security wage base.
  • Withholding counts in equal parts on each due date, which is how the IRS treats it unless you show the actual dates.
  • Last year was a full 12-month tax year and you filed a return for it.

What it ignores

  • Credits, a prior-year overpayment applied to this year, and the annualized income installment method.
  • The farming and fishing rules and the $75,000 threshold for married filing separately.
  • State and local income tax, NIIT, and the self-employed health insurance and retirement plan deductions.
  • QBI phase-ins for specified service businesses and the W-2 wage and property limits at higher incomes.

Sources

Primary sources

  1. 26 U.S. Code Section 1401: rate of self-employment tax: 12.4%, 2.9% and 0.9% Additional Medicare rates
  2. 26 U.S. Code Section 1402: definitions: net earnings from self-employment and the 92.35% factor
  3. Instructions for Schedule SE (Form 1040): line-by-line SE tax computation and wage-base coordination
  4. SSA: 2026 contribution and benefit base: $184,500 Social Security wage base
  5. Instructions for Form 8959: Additional Medicare Tax: thresholds by filing status
  6. 26 U.S. Code Section 164: taxes: subsection (f): income-tax deduction for half of SE tax
  7. IRS Revenue Procedure 2025-32: 2026 tax brackets and standard deduction
  8. 26 U.S. Code Section 199A: qualified business income: 20% QBI deduction and its limits
  9. Instructions for Form 8995: QBI deduction simplified computation: taxable income limit on the deduction
  10. IRS: estimated taxes: quarterly payments and due dates
  11. 26 U.S. Code Section 6654: failure to pay estimated tax: due dates, the 90%, 100% and 110% required annual payment, the $1,000 exception, withholding treated as paid evenly
  12. 2026 Form 1040-ES: estimated tax for individuals: 2026 payment due dates and the estimated tax worksheet

Written by Bryan Martin, CPA, Managing Partner and Founder of Taxstra. Last reviewed October 20, 2026. Taxstra is a CPA firm serving 1,000+ clients in all 50 states.

Educational, not individualized tax advice.

How Self-Employment Tax Actually Works

A W-2 employee and their employer split FICA taxes (Social Security and Medicare) 50/50. Self-employed, you are both parties, so you pay the full 15.3%, but on 92.35% of profit rather than 100%, and half of what you pay comes back as an income-tax deduction. If clients or apps pay you through a platform, some of that income may arrive on a Form 1099-K; the SE tax math is the same either way. On top of that, most self-employment profit qualifies for the 20% QBI deduction, which reduces income tax (though not SE tax).

The structural escape hatch is entity choice: once profit consistently clears about $75,000, an S-corp election lets you split income into a reasonable salary (which pays payroll tax) and distributions (which don't). And every dollar you shelter in a solo 401(k) cuts income tax while building retirement savings.

One boundary worth knowing: a nanny or other household worker is an employee, not a 1099 contractor, so their wages fall under the nanny tax rules rather than self-employment tax.

Key Insight

Deadlines matter as much as math

The IRS charges interest-based penalties for underpaying during the year, even if you pay in full by April. If this calculator shows a meaningful number, put the four quarterly dates on your calendar, or check our full deadline calendar.

Self-employed? Sort out the structure before the next estimate.

Self-employment tax runs on every dollar of profit until you change the structure. Whether an S corp with a reasonable salary is worth its costs depends on your profit, wages, and states. Book a free 30-minute consultation with our team to talk through your business and whether Taxstra is a fit. See how we work with the self-employed and S corp owners.

Tax planning slots are limited before year-end.

Common Questions

How much is self-employment tax in 2026?

Self-employment tax is 15.3%. 12.4% for Social Security plus 2.9% for Medicare, applied to 92.35% of your net self-employment earnings. The Social Security portion stops at the annual wage base ($184,500 in 2026); the Medicare portion has no cap, and an extra 0.9% applies above $200,000 of income ($250,000 married filing jointly). This is on top of regular income tax.

How do you calculate self-employment tax?

Multiply net self-employment profit by 92.35%, then multiply that by 15.3%. On $100,000 of 1099 profit: $100,000 x 92.35% = $92,350, and $92,350 x 15.3% = about $14,130 of self-employment tax. Half of that, about $7,065, is deductible when figuring income tax. Income tax is calculated separately on top, so the amount to set aside is the self-employment tax plus your income tax on the profit, which the calculator above estimates together.

Why is self-employment tax so high?

It isn't a separate penalty, it's both halves of Social Security and Medicare. As a W-2 employee, your employer pays half (7.65%) invisibly. Self-employed, you pay both halves, but you get two offsets: half of the SE tax is deductible against income tax, and qualified business income is generally eligible for the 20% QBI deduction.

How do I calculate quarterly estimated taxes?

Start with expected annual tax, then account for withholding, credits, prior payments, the applicable safe harbor, and payment-period timing. The quarterly section of this calculator takes last year's tax, your withholding and the payments you have made, and shows the next installment under the smaller safe harbor. Use Form 1040-ES and consider the annualized-income method if income is uneven.

What does the quarterly tax calculator for 1099 income show?

It shows your self-employment tax for the year and the next estimated payment after withholding and payments made, using the smaller of the prior-year and current-year safe harbors. It is an estimate, not a recommended payment; the rules are on our estimated tax payments page.

How can I reduce self-employment tax?

Keep accurate records of legitimate business expenses and evaluate entity structure using compensation, payroll costs, operating states, and the full tax picture. There is no universal profit threshold at which an S corporation is best. Retirement deductions and self-employment-tax calculations are separate questions.

Do I pay self-employment tax if I also have a W-2 job?

Yes, on your self-employment profit, but with one break: your W-2 wages count first against the Social Security wage base. If your day job already pays you above the wage base, your side income owes only the Medicare portion (2.9%, plus the 0.9% surtax where applicable), not the full 15.3%.

Is the first $400 of self-employment income tax-free?

Below $400 of net self-employment earnings you owe no SE tax and generally do not need to file Schedule SE. At $400 or above, SE tax applies to the whole amount (computed on 92.35% of net earnings), not just the excess.

Deduction guides by line of work

1099 Tax Deductions →Gig Driver Tax Deductions →Farm Tax Deductions →Airbnb Tax Deductions →

Stop guessing at quarterlies

After you engage, we work out your estimated payments, file the elections that shrink the bill, and handle the returns. Book a free 30-minute call with our team to talk through your next steps.

Tax planning slots are limited before year-end.

Self-employment tax adding up?

Once profit is steady, the questions become entity choice, owner pay, and quarterly estimates. Look at them together before electing anything.

Explore S-corp CPA services →