Employees split Social Security and Medicare tax with their employer. The self-employed pay both halves themselves — this calculator adds up exactly what that comes to.
How it works
Net profit is first multiplied by 92.35% to get net earnings — an adjustment that keeps the self-employed on comparable footing to an employee rather than taxing the same dollar twice. Social Security tax of 12.4% applies up to the annual wage base; Medicare’s 2.9% applies to all net earnings, with an extra 0.9% surtax above a higher threshold.
The deductible half
Half of the total self-employment tax is deductible against income tax — it reduces taxable income, not the self-employment tax bill itself. This calculator reports it separately so it isn’t mistaken for a reduction in what’s actually owed on Schedule SE.
How to use this calculator
- Enter net self-employment profit for the year.
- Choose a filing status, which sets the additional Medicare threshold.
Frequently asked questions
Is self-employment tax the same as income tax?
No — it’s entirely separate, covering only Social Security and Medicare. Income tax is calculated independently on top of it.
Why is the tax calculated on 92.35% of profit, not the full amount?
It approximates removing the employer-equivalent share an employee’s wages wouldn’t otherwise include, keeping the calculation roughly consistent with how an employee’s FICA tax works.
Does the Social Security cap mean high earners pay less self-employment tax overall?
Only the Social Security portion caps — Medicare, including the additional surtax, keeps applying with no ceiling as net earnings rise.
