Self-employment tax covers Social Security and Medicare for people who work for themselves. As both employer and employee, you pay both halves of FICA: a combined 15.3% on the first $176,100 of net self-employment income for 2025.
The SE Tax Formula
SE Tax Base = Net Profit × 0.9235 SE Tax = SE Base × 12.4% (SS, up to $176,100) + SE Base × 2.9% (Medicare) Half SE Deduction = SE Tax ÷ 2 Taxable Income = Net Profit − Half SE − Standard Deduction Total Tax = SE Tax + Federal Income Tax on Taxable Income
2025 SE Tax Rates
12.4% Social Security on the first $176,100 of SE income
2.9% Medicare on all SE income (no wage cap)
0.9% Additional Medicare on SE income above $200,000 (single)
Half of SE tax is deductible as an above-the-line adjustment
Who Is This Calculator For?
Anyone with net profit from freelancing, consulting, or a sole proprietorship needs to pay SE tax and make quarterly estimated payments.
Freelancers and consultants
Anyone billing clients directly who files Schedule C and receives 1099-NEC income.
Gig workers
Rideshare, delivery, and marketplace workers whose platforms do not withhold taxes.
Small business owners
Sole proprietors whose business profit flows directly to their personal return.
New to self-employment
W-2 workers transitioning to self-employment who need to plan quarterly payments for the first time.
How to Use the Calculator
1
Enter net business profit
This is revenue minus legitimate business expenses, the amount reported on Schedule C, Line 31. Do not enter gross revenue.
2
Add other income (optional)
If you also have W-2 wages or investment income, enter the annual total. It affects which federal brackets apply.
3
Select your filing status
Single, Married Filing Jointly, or Head of Household. This determines your standard deduction and federal brackets.
4
Click Calculate
The results card shows SE tax, income tax, and your quarterly payment amount for each of the four 2025 due dates.
5
Pay through IRS Direct Pay or EFTPS
Use the quarterly figure to make estimated payments at irs.gov/payments before each due date.
Example Calculation
Marcus is a single freelance marketing consultant with $95,000 net profit and no other income in 2025.
SE tax base ($95,000 × 0.9235)$87,733
Social Security ($87,733 × 12.4%)-$10,879
Medicare ($87,733 × 2.9%)-$2,544
SE Tax total$13,423
Half SE deduction-$6,711
Standard deduction (single)-$14,600
Taxable income$73,689
Federal income tax (22% bracket)-$11,696
Total tax$25,119
Quarterly estimated payment~$6,280
Marcus's effective rate is 26.4% on his $95,000 net profit. He sets aside $6,280 each quarter (April 15, June 16, September 15, January 15) to avoid an underpayment penalty.
Common Mistakes to Avoid
!
Skipping quarterly payments
SE tax is due throughout the year. Waiting until April results in an underpayment penalty even if you pay the full balance at filing.
!
Using gross revenue instead of net profit
SE tax applies to profit after business expenses. Deduct equipment, software, home office, and mileage before entering the figure here.
!
Missing the half-SE-tax deduction
Half of what you pay in SE tax is deductible on Schedule 1. Skipping this raises your taxable income and your income tax unnecessarily.
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Not tracking the Social Security wage base
In 2025, Social Security tax stops at $176,100 of self-employment income. Earnings above that only owe the 2.9% Medicare portion.
!
Forgetting state self-employment taxes
Some states have their own SE-related taxes or require quarterly state estimated payments. This calculator only covers federal SE tax.
Frequently Asked Questions
The self-employment tax rate is 15.3% (12.4% Social Security plus 2.9% Medicare), applied to 92.35% of your net profit. Above the $176,100 Social Security wage base, only the 2.9% Medicare portion continues. Earners above $200,000 (single) also owe an extra 0.9% Additional Medicare Tax.
Source for the 92.35% SE base calculation, Social Security wage base ($176,100), and 15.3% combined FICA rate.
2
IRS Publication 505: Tax Withholding and Estimated Tax
Source for quarterly estimated payment due dates and the safe harbor rule for avoiding underpayment penalties.
3
IRS Rev. Proc. 2024-40: 2025 Inflation Adjustments
Source for 2025 federal tax brackets, standard deductions ($14,600 single / $29,200 MFJ), and the $176,100 Social Security wage base.
R
Rachel Torres, CPA
Certified Public Accountant, 11 years in self-employed and small business tax
Rachel specializes in self-employed clients and quarterly tax planning. She reviewed the SE tax formula, bracket logic, and 2025 rate inputs on this page.
Reviewed: April 2025Tax year: 2025
2025 SE Tax Rates
Social Security rate
12.4%
Medicare rate
2.9%
Combined SE rate
15.3%
SS wage base
$176,100
Add'l Medicare
0.9% above $200k
Standard deduction (single)
$14,600
Standard deduction (MFJ)
$29,200
Common SE Deductions
Home office (regular/exclusive use)
Business mileage ($0.70/mile 2025)
Health insurance premiums
SEP-IRA contributions (up to 25% of net)
Software, equipment, subscriptions
Professional development and education
Pro Tip
A SEP-IRA lets you contribute up to 25% of net SE income (max $69,000 for 2025). That contribution reduces your AGI, lowering both federal income tax and state tax, while building retirement savings.