Self Employment Tax Calculator

Calculate self-employment tax including Social Security and Medicare taxes for freelancers, contractors, and business owners. Estimate quarterly tax payments and understand your tax obligations.

What Is a Self-Employment Tax Calculator?

A self-employment tax calculator estimates the Social Security and Medicare taxes owed by individuals who work for themselves, including freelancers, independent contractors, sole proprietors, and gig workers. Unlike W-2 employees whose employers withhold and match FICA taxes, self-employed individuals are responsible for paying both the employer and employee shares of these taxes.

Self-employment tax is separate from federal income tax and applies to net earnings from self-employment of $400 or more. The combined rate of 15.3% represents a significant tax obligation that catches many new freelancers off guard. This calculator breaks down the components and shows the deductible portion, quarterly payment amounts, and effective rate.

How Self-Employment Tax Works

The calculation follows a specific sequence mandated by the IRS:

Step 1: Determine net self-employment income. This is gross revenue minus all allowable business expenses (Schedule C net profit).

Step 2: Multiply net income by 92.35% to find the taxable self-employment earnings. This reduction accounts for the employer-equivalent portion of the tax.

Step 3: Apply the Social Security tax rate of 12.4% to the lesser of your taxable SE earnings or the remaining Social Security wage base ($168,600 for 2024, reduced by any W-2 wages).

Step 4: Apply the Medicare tax rate of 2.9% to all taxable SE earnings with no cap.

Step 5: If combined earnings (SE plus W-2) exceed $200,000 for single filers or $250,000 for married filing jointly, apply an additional 0.9% Medicare tax on the excess.

Step 6: Add all components together for the total self-employment tax.

Half of the total SE tax is deductible as an above-the-line income tax deduction, reducing your adjusted gross income.

How to Use This Calculator

Enter your net self-employment income. This is your total freelance or business revenue minus all business expenses. Use the net profit figure from Schedule C or your accounting records.
Select your filing status. This affects the threshold for the additional Medicare tax. Married filing jointly has a higher threshold ($250,000) than single or head of household ($200,000).
Enter W-2 income if applicable. If you also have a regular job with W-2 wages, enter that amount. It reduces the Social Security wage base available for your SE income, potentially lowering your Social Security tax.
Review the breakdown. The results show each tax component separately, the deductible portion, quarterly estimated payments, and the effective rate on your total net income.

Worked Examples

Example 1: Full-Time Freelancer

Net SE income of $80,000, single, no W-2 income. Taxable SE earnings: $80,000 x 0.9235 = $73,880. Social Security tax: $73,880 x 0.124 = $9,161. Medicare tax: $73,880 x 0.029 = $2,143. Total SE tax: $11,304. Deductible: $5,652. Effective rate on net income: 14.13%.

Example 2: Side Hustle with Day Job

Net SE income of $25,000, single, plus $120,000 in W-2 wages. Taxable SE: $23,088. Remaining SS wage base: $168,600 - $120,000 = $48,600. Since $23,088 is below $48,600, full SS tax applies. Total SE tax is approximately $3,554.

Example 3: High-Earning Self-Employed

Net SE income of $250,000, single. Taxable SE: $230,875. SS tax applies only to $168,600, so SS tax: $168,600 x 0.124 = $20,906. Medicare: $230,875 x 0.029 = $6,695. Additional Medicare on earnings over $200,000: $30,875 x 0.009 = $278. Total SE tax: $27,879.

Example 4: Married with Mixed Income

Net SE income of $150,000, married filing jointly, spouse has $130,000 W-2 income. Remaining SS base: $168,600 - $130,000 = $38,600. Taxable SE: $138,525. SS tax on $38,600: $4,786. Medicare on $138,525: $4,017. Combined earnings ($280,000) exceed $250,000 threshold, so additional Medicare applies on $30,000: $270. Total SE tax: $9,073.

Tips and Common Mistakes

Set aside 25-30% of income for taxes. Self-employment tax plus income tax can total 25 to 35 percent or more of net earnings. Setting aside money from each payment you receive prevents a surprise at tax time.

Make quarterly estimated payments. The IRS expects tax payments throughout the year, not just at filing time. Missing quarterly deadlines incurs underpayment penalties. The calculator shows your quarterly SE tax amount.

Deduct all legitimate business expenses. Every dollar of business expense reduces your net SE income and your SE tax. Track expenses meticulously and deduct home office costs, equipment, software, mileage, health insurance premiums, and professional services.

Do not forget the income tax deduction. Half of your SE tax is deductible on your income tax return. This is an above-the-line deduction available regardless of whether you itemize.

Understand the W-2 interaction. If you have both W-2 wages and SE income, your W-2 wages reduce the Social Security wage base for SE tax purposes. This can significantly lower your SE tax when your combined earnings approach or exceed the wage base.

Consider an S-Corp election for high earners. Self-employed individuals with consistent high income may benefit from electing S-Corp status. As an S-Corp owner, you pay yourself a reasonable salary (subject to FICA) and take remaining profits as distributions (not subject to SE tax). Consult a tax professional to determine if this strategy is appropriate for your situation.

Frequently Asked Questions

What is self-employment tax?

Self-employment tax is the Social Security and Medicare tax that self-employed individuals pay on their net earnings. It is the equivalent of the FICA taxes that employers and employees split for W-2 workers. The combined rate is 15.3% (12.4% for Social Security and 2.9% for Medicare), applied to 92.35% of net self-employment income. Self-employed workers pay both the employer and employee portions.

Why is only 92.35% of my income taxed?

The 92.35% factor (equivalent to multiplying by 0.9235) accounts for the employer-equivalent portion of the SE tax. W-2 employees do not pay income tax on their employer's share of FICA. To put self-employed individuals on equal footing, the IRS reduces the taxable base by 7.65% (half of 15.3%). This means the effective SE tax rate on total net income is approximately 14.13% rather than the full 15.3%.

What is the Social Security wage base?

The Social Security wage base is the maximum amount of earnings subject to Social Security tax in a given year. For 2024, the wage base is $168,600. Earnings above this amount are not subject to the 12.4% Social Security portion of SE tax. However, there is no cap on Medicare tax, which applies to all earnings. If you also have W-2 income, your combined earnings count toward the wage base.

What is the additional Medicare tax?

An additional 0.9% Medicare tax applies to combined earnings (self-employment plus W-2 wages) exceeding $200,000 for single filers or $250,000 for married filing jointly. This additional tax applies only to the Medicare portion and only to the amount above the threshold. It was introduced by the Affordable Care Act and is not split between employer and employee.

Can I deduct self-employment tax?

You can deduct the employer-equivalent portion of your SE tax (50% of the total) as an above-the-line deduction on your income tax return. This deduction reduces your adjusted gross income and is available whether you itemize or take the standard deduction. It does not reduce your SE tax itself, only your income tax.

When are estimated tax payments due?

Self-employed individuals must make quarterly estimated tax payments by April 15, June 15, September 15, and January 15 of the following year. These payments cover both self-employment tax and income tax. Failing to make adequate estimated payments may result in underpayment penalties. The calculator divides your annual SE tax by four to show the quarterly amount.

Does SE tax apply to all freelance income?

SE tax applies to net earnings from self-employment of $400 or more per year. This includes freelance work, gig economy income, sole proprietorship profits, and general partnership income. It does not apply to passive income such as rental income, interest, dividends, or capital gains, unless you are a real estate professional or dealer.

How do W-2 wages affect my SE tax?

If you have both W-2 wages and self-employment income, your W-2 wages count first toward the Social Security wage base. Only the remaining wage base applies to your SE income for the Social Security portion. For example, if you earn $150,000 in W-2 wages, only $18,600 of your SE income is subject to Social Security tax ($168,600 - $150,000). Medicare tax still applies to all SE income regardless of W-2 wages.