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US · 2025

Self-Employment Tax Calculator

Calculate your US self-employment tax (Social Security + Medicare) and estimate your Section 199A QBI deduction. Covers the 2024 Social Security wage base of $168,600.

Last reviewed: 5 September 2025Source: HMRC — Tax ratesUpdated every: tax year
Self-Employment Tax Calculator · USUS Tax

SE Tax

$11,303.64

Deductible Half

$5,651.82

QBI Deduction (est.)

$14,869.64

Effective SE Rate

14.13%

Rates & sources

UK tax rates and thresholds, as published by HMRC. Scotland and Wales have devolved rates for income tax and property transactions.

Source: HMRC — Tax rates — figures refreshed at the start of each tax year.

When to use this calculator

  • Before accepting a pay change, bonus, pension contribution, or salary-sacrifice option.
  • When you want to compare employed, self-employed, or dividend-based income scenarios.
  • When you need a simple take-home estimate before running payroll or filing returns.
  • When you are approaching the £100,000 income level and want to understand the personal allowance taper effect.
  • When you are planning a salary sacrifice arrangement and need to see the net pay impact before agreeing terms.

A realistic US planning example

Use these sample inputs as a quick scenario test, then change one variable at a time to compare outcomes.

Net Self-Employment Profit ($)

80000

After entering these figures, review se tax, deductible half and qbi deduction (est.) together rather than in isolation — each metric tells a different part of the story. Then rerun the tool with one input adjusted to see which variable has the biggest effect on all three outputs before you settle on a plan.

How to read your results

SE Tax

Review this figure alongside your gross income so you can understand the true cost of deductions and plan around any thresholds before the tax year closes. If the figure looks higher than expected, check whether any pension or gift-aid contributions could reduce your taxable income.

Deductible Half

Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.

QBI Deduction (est.)

Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.

Effective SE Rate

Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.

Method & assumptionsAuthoritative sources

This calculator estimates US self-employment tax for sole proprietors, single-member LLC owners, freelancers, and independent contractors. SE tax is computed on 92.35% of net profit — this adjustment accounts for the fact that employees do not pay FICA on the portion of wages equal to the employer's payroll tax contribution. For 2024, the Social Security component of 12.4% applies only to the first $168,600 of SE income; the Medicare component of 2.9% applies to all SE income with no ceiling. An additional 0.9% Medicare surtax applies above $200,000 for single filers but is not modelled here due to its dependence on total household income.

The deductible half of SE tax is the IRS's mechanism for giving self-employed individuals the same after-tax treatment as employees whose employers' FICA contributions are not included in employees' gross income. The QBI deduction estimate shown is based on 20% of net profit before the SE deduction, capped at 20% of adjusted income after the SE deduction, and does not account for the W-2 wage limitation or specified service trade restrictions that apply at higher income levels. Always use Schedule SE (Form 1040) and consult a CPA or tax professional for your final return.

Common mistakes

  • !Entering gross income when you really want take-home pay, or vice versa.
  • !Ignoring pension contributions, deductions, or local tax rules that change the result.
  • !Comparing monthly and annual figures without standardising them first.
  • !Overlooking the National Insurance threshold changes that apply mid-year when rates or bands are adjusted in a Budget.
  • !Assuming a salary sacrifice benefit reduces take-home pay by the full gross amount, rather than only the after-tax cost.

What to do next

  • Check the same scenario with related pay or deduction calculators to see the full picture.
  • Keep a copy of the assumptions you used so you can compare next tax year or pay period accurately.
  • Read the related guides below if you are choosing between multiple income or deduction options.
  • If you are self-employed, run the self-employment tax calculator alongside this result to compare the net position against employed income.
  • Check whether increasing your pension contribution by even one or two percent changes the take-home significantly — use the pension calculator next.

Frequently asked

Self-employment (SE) tax covers Social Security (12.4%) and Medicare (2.9%) contributions that employees normally split with their employer. As a self-employed person you pay both halves, totalling 15.3% on 92.35% of your net self-employment income (the 92.35% factor accounts for the employer portion deduction). For 2024, Social Security tax only applies to the first $168,600 of SE income; Medicare applies to all SE income with an additional 0.9% on amounts above $200,000 ($250,000 for joint filers).

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