Understanding Self-Employment Tax (And How to Reduce It)

Self-employment tax is the line that surprises people in their first year of freelancing, and it keeps surprising them because most explanations stop at "it's 15.3%." That number is accurate and close to useless for planning. It is applied to a smaller figure than your profit, half of it comes back as a deduction, and above a certain income it starts to shrink as a share of what you earn.

The mechanics are worth understanding once, because they explain why some popular tax advice does nothing for this particular bill.

The 15.3% is charged on 92.35% of your profit

Self-employment tax is Social Security and Medicare tax for people who do not have an employer paying half. Employees split those taxes with a company: 7.65% out of the paycheck, 7.65% from the employer. When you work for yourself you pay both halves, which is where 15.3% comes from.

Before that rate applies, your net profit from Schedule C is multiplied by 0.9235. The purpose of that step is to approximate the employer half, which an employer would have deducted as a business expense before profit was calculated. So the amount your tax is figured on is always about 7.65% smaller than your profit, and the effective rate on profit works out to roughly 14.1%.

The two components behave differently. The 12.4% Social Security piece applies only up to the wage base, which the Social Security Administration set at $184,500 for 2026. The 2.9% Medicare piece has no ceiling at all, and single filers add another 0.9% on self-employment earnings above $200,000.

Add federal income tax to that same $80,000 (single filer, standard deduction of $16,100 for 2026, claiming the qualified business income deduction) and the total federal bill lands near $16,650, or about 21% of profit. Self-employment tax is roughly two-thirds of it. This is why setting aside 25% to 30% of every payment is the standard advice: income tax alone would not require it.

Where the tax stops climbing

Because 14.1% is flat, self-employment tax is unusual among federal taxes: it does not get proportionally worse as you earn more. It gets better, though not until fairly high income.

Net profit	Amount subject to SE tax	SE tax owed	Share of profit
$25,000	$23,088	$3,532	14.1%
$50,000	$46,175	$7,065	14.1%
$80,000	$73,880	$11,304	14.1%
$120,000	$110,820	$16,955	14.1%
$250,000	$230,875	$29,573	11.8%

2026 figures, rounded to the nearest dollar. The $250,000 row is lower as a share of profit because Social Security tax stopped at the $184,500 wage base. It excludes the additional 0.9% Medicare tax on self-employment earnings above $200,000 for a single filer, which would add about $278.

If your profit sits between $30,000 and $150,000, your self-employment tax is 14.1% and no amount of income-tax planning will change that percentage. The only way to pay less is to have less profit, or to change how the profit is characterized.

Half of it comes back, but not the way people expect

You deduct half your self-employment tax on Schedule 1 of Form 1040. On $80,000 of profit that is $5,652 knocked off your adjusted gross income. For a single filer at that income who claims the qualified business income deduction, taxable income sits in the 12% bracket, so the deduction is worth about $540; in the 22% bracket it would be worth about $1,240.

Notice what it does not do. The deduction reduces income tax, not self-employment tax. Self-employment tax is calculated first, on Schedule SE, from your Schedule C profit. Nothing on the 1040 below that line reaches back and changes it. That single fact explains most of the confusion in the next section.

Lever one: business expenses, which count twice

Every legitimate business expense reduces Schedule C profit, and Schedule C profit is the input to both taxes. An expense saves 14.1% in self-employment tax and also lowers income tax at your marginal rate (somewhat less if you claim the qualified business income deduction, which shrinks along with profit). Combined, an ordinary business expense is worth roughly 30 to 36 cents on the dollar to someone in the 22% bracket.

Many freelancers underuse this lever, and it needs no new entity or legal work. It needs records.

Two rules keep this defensible. The expense has to be ordinary and necessary for your line of work, and you need the documentation to support it, which for mixed-use items means a reasonable basis for the business share. Guessing at 80% for a phone with no record behind it is the kind of number that falls apart under examination. Recording each expense when it happens, with the receipt attached, is what makes the business share defensible later. Self Employment Toolkit (from the same publisher as this site) has a free expense tracker whose categories map to Schedule C lines, if you want somewhere to do that. Our guide to business deductions for freelancers covers the commonly missed categories, and the home office deduction is usually the largest one people skip.

Lever two: the S-Corp election, at high and steady profit

The other lever changes what your profit is called. Elect S-Corp status and you split the money into a reasonable salary (payroll tax applies) and a distribution (it does not). The distribution portion escapes the 15.3%.

The saving is real. It is also smaller than it sounds and comes with costs: payroll service, a separate corporate return, possible state entity taxes and a smaller qualified business income deduction, because wages you pay yourself are not qualified business income. Below roughly $100,000 of durable profit those costs often eat the entire benefit. We covered the case for it in When to Elect S-Corp Status and the math in S-Corp Tax Advantages, then took the other side in When an S-Corp Election Is the Wrong Move.

If you are reading this in August and your profit has cleared $100,000 for two straight years, the useful step is to model your own numbers with your own state before year-end. Form 2553 is due by March 15 of the year the election takes effect, which means the decision belongs to this fall, not next spring.

What does not reduce self-employment tax

This list matters more than the levers, because acting on a false one costs real money in wasted planning.

Retirement contributions. A solo 401(k) or SEP-IRA contribution is deducted on Schedule 1, after Schedule SE is done. Contributing $24,500 to a solo 401(k) (the 2026 employee deferral limit) can save several thousand dollars of income tax and changes your self-employment tax by exactly zero. The account is still worth opening. It just is not an answer to this particular problem.

The qualified business income deduction. The 20% deduction under section 199A reduces taxable income and has no effect on Schedule SE.

Your standard or itemized deductions. Same reason. They live below the line where self-employment tax was already computed.

Forming an LLC. A single-member LLC is disregarded for federal tax purposes by default. You still file Schedule C and Schedule SE. The LLC is a liability structure, not a tax structure, unless you make a separate election on top of it.

Being paid late or not receiving a 1099. Income is income when you receive it. The 1099-NEC threshold ($2,000 for payments made in 2026, up from $600) governs when a client must issue a form, not whether you owe tax.

Where to put this in the next month

The Q3 estimated payment is due Sept. 15, which makes August the sensible time to check whether your withholding math still matches your year.

• Pull your year-to-date net profit, annualize it, and multiply by 0.141 to get a working self-employment tax figure for the year.
• Compare that to what you have paid in so far across the April and June installments. If you are short, add the gap to the Sept. 15 payment rather than waiting for April.
• Go through three months of bank and card statements looking for business costs you never recorded. Small recurring charges are the easiest to miss.
• Confirm your business-use records exist for anything mixed-use: mileage, phone, home office square footage.
• If profit will clear $100,000 for a second or third year, book time this fall to model an S-Corp election with your actual state figures.
• Open a solo 401(k) before Dec. 31 if you want one for 2026. It will not touch your self-employment tax, and it is still the largest income-tax lever most freelancers have.

Self-employment tax is a fixed cost of working for yourself, and treating it as one makes the rest of the planning simpler. Take 14.1% of profit off the top, set it aside as it arrives, and spend your energy on the two things that genuinely move it: recording every legitimate expense, and revisiting your entity choice once profit is high enough and steady enough to justify the overhead.