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Self Employment Tax Estimator

The Self Employment Tax Estimator approximates Social Security and Medicare-style payroll taxes on net self-employment earnings. It starts with business profit, applies an earnings adjustment factor, caps the Social Security portion at a user-entered wage base after accounting for wages, and adds Medicare and optional additional Medicare tax.

Default values reflect a U.S.-style structure, but all rates, thresholds, and limits are editable. This calculator estimates payroll-type self-employment tax only and does not include regular income tax.

Estimate inputs

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Result
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Estimated self-employment tax
Net earnings subject to calculation—
Social Security portion—
Medicare portions—
Estimated deductible half—

1. Enter net business profit

Use income minus allowable business expenses.

2. Confirm the earnings factor

Keep the default only when it matches the method you intend to model.

3. Enter covered wages

Add wages already counted toward the Social Security wage base.

4. Set annual limits and rates

Update the wage base, rates, and additional Medicare threshold for the relevant year and filing status.

5. Review components

Check Social Security, Medicare, additional Medicare, and the deductible half estimate.

Net earnings = Net profit × Earnings factor Social Security tax = min(Net earnings, max(0, Wage base − wages)) × SS rate Medicare tax = Net earnings × Medicare rate Additional Medicare tax = max(0, Net earnings + wages − threshold) × additional rate

The estimate excludes regular income tax and special adjustments that may apply on an official return.

What the result means

The main result is an estimate based entirely on the values and rates entered. Use the supporting rows to see the taxable base and major components.

Results are planning estimates only. Tax rules, exemptions, filing obligations, and rates vary by jurisdiction and may change; verify the figures with the relevant tax authority or a qualified adviser.

Given: $100,000 net profit, 92.35% earnings factor, no covered wages, a $184,500 wage base, 12.4% Social Security, and 2.9% Medicare.

Calculation: Net earnings = $92,350. Social Security tax = $11,451.40. Medicare tax = $2,678.15. Total = $14,129.55.

Result: Estimated self-employment tax is $14,129.55.

Does this include income tax?

No. It estimates payroll-type self-employment tax separately from income tax.

Why is net profit multiplied by an earnings factor?

Some systems calculate self-employment tax on an adjusted portion of net profit rather than the full amount.

Why enter wages?

Covered wages may use part or all of the annual Social Security wage base before self-employment earnings are considered.

Is the deductible half a tax credit?

No. In a U.S.-style calculation it is generally an income adjustment, not a dollar-for-dollar credit.

Which values should I update each year?

Review the wage base, rates, thresholds, filing-status rules, and any official worksheet changes.