On $85,000 of Self-Employed Income, Set Aside $5,307.50 Every Quarter
Self-employment tax is the line that catches people out: 15.3% on top of income tax, with no employer paying half. Here is the full calculation, the safe-harbour rule that prevents penalties, and why 25% to 30% is the figure to move on receipt.
The first year of self-employment produces a specific and unpleasant surprise. You earned $85,000, you set aside what felt like a sensible amount, and the bill is far larger than the tax tables suggested. The reason is a tax that employees pay without ever seeing it.
Two taxes, not one
As an employee, Social Security and Medicare are funded by two contributions of 7.65% each, one from you and one from your employer. You only ever see your half. Self-employed people pay both, combined into the self-employment tax at 15.3%, which applies before any income tax is calculated.
Two provisions soften it. The tax applies to 92.35% of net earnings rather than the full amount, and you deduct half of the resulting tax when computing adjusted gross income. Neither changes the fact that it is the larger of the two taxes at this income level.
The full calculation on $85,000
| Step | Amount |
|---|---|
| Net self-employment income | $85,000.00 |
| Multiplied by 92.35% to get the SE tax base | $78,497.50 |
| Self-employment tax at 15.3% | $12,010.12 |
| Adjusted gross income (after deducting half the SE tax) | $78,994.94 |
| Less standard deduction | $64,394.94 taxable |
| Federal income tax | $9,219.89 |
| Total federal tax | $21,230.00 |
| Quarterly payment | $5,307.50 |
The total is 25.0% of net income, and self-employment tax accounts for more of it than income tax does. This is why advice to set aside 15% or 20% is dangerously low for self-employed people, even though it would be roughly right for an employee at the same income.
When payments are due
The United States operates a pay-as-you-go system. Employees satisfy it through withholding on every paycheque; the self-employed satisfy it through four estimated payments. The periods are not equal quarters, which catches people out.
| Payment | Income period covered | Typical due date |
|---|---|---|
| 1st | January 1 to March 31 | April 15 |
| 2nd | April 1 to May 31 | June 15 |
| 3rd | June 1 to August 31 | September 15 |
| 4th | September 1 to December 31 | January 15 of the following year |
Note that the second period covers two months and the fourth covers four. Dividing your annual estimate into four equal payments is standard and acceptable, but if your income is seasonal you may be underpaying early in the year even while paying the correct annual total.
The safe harbour that prevents penalties
Underpayment penalties are charged as interest on the shortfall for the period it was outstanding, so they accrue even if you pay everything by the filing deadline. The way to avoid them is to satisfy one of the safe harbour rules, which protect you regardless of how much you eventually owe.
- Pay at least 90% of the current year's total tax liability, or
- Pay at least 100% of the prior year's total tax liability, rising to 110% if your prior-year adjusted gross income exceeded a specified threshold.
The prior-year rule is the practical one, because it depends on a number you already know rather than a year you have not finished. If your income is rising, paying 100% of last year's tax protects you from penalties even though you will owe considerably more at filing. You still have to pay the difference, but you pay it in April without a penalty attached.
A withholding trick worth knowing
Estimated payments are credited on the date paid, so a shortfall discovered in November cannot be fixed retroactively for earlier periods. Withholding is treated differently: it is deemed to have been paid evenly across the year regardless of when it actually occurred.
If you or a spouse also has employment income, increasing withholding late in the year can therefore cure an earlier underpayment in a way that a large fourth estimated payment cannot. This is genuinely useful for people whose self-employment income is unpredictable, and it is one of the few situations where a December adjustment fixes a March problem.
What reduces the bill legitimately
- Deduct every ordinary and necessary business expense. Software, equipment, professional insurance, business travel, and professional development all reduce net self-employment income, which reduces both taxes rather than just income tax.
- Claim the home office deduction if you qualify. It requires regular and exclusive business use of a defined space, and the simplified method avoids most of the record-keeping burden.
- Contribute to a self-employed retirement plan. A SEP-IRA or solo 401(k) allows substantially higher contributions than a standard IRA, and contributions reduce taxable income. Note that they reduce income tax but generally not self-employment tax.
- Deduct self-employed health insurance premiums. This is an above-the-line deduction available without itemising, subject to conditions about eligibility for employer coverage.
- Track the qualified business income deduction. Many self-employed people can deduct a percentage of qualified business income, subject to income thresholds and business-type limitations. It is worth confirming whether you qualify, since it is substantial when available.
Each of these is a legitimate reduction rather than a deferral. Between deductible expenses, retirement contributions, and the qualified business income deduction, the effective rate on self-employment income is frequently well below the 25% headline figure, but only for people who track expenses properly through the year rather than reconstructing them in April.
Estimate federal income taxIncome Tax CalculatorCompare against an equivalent salaryTake-Home-Paycheck CalculatorFrequently asked questions
Which tax year do these figures use?
The self-employment tax rate, standard deduction, and bracket thresholds used here are 2024 federal figures for a single filer, and no state tax is included. Brackets and the standard deduction are adjusted annually, and the Social Security portion of self-employment tax applies only up to an annual wage base that also changes each year. Confirm current figures before filing, and add your state's requirements, which have their own deadlines and rules.
What if my income is unpredictable?
Two approaches. The simplest is to pay 100% of last year's tax in four equal instalments, which satisfies the safe harbour regardless of what you actually earn this year. The alternative is the annualised income instalment method, which lets you pay based on income actually received in each period and is worth the extra paperwork if your income is heavily seasonal. Either way, moving a fixed percentage of each payment into a separate account as it arrives is what makes the deadlines manageable.
Do I need to make estimated payments in my first year?
Generally yes, if you expect to owe a meaningful amount when you file. There is an exception worth knowing: if you had no tax liability in the prior year and were a citizen or resident for the whole of that year, you may not owe a penalty for underpaying in the current year. This gives genuine breathing room in a first year of self-employment, but it does not remove the eventual liability, so setting money aside remains essential.
Does self-employment tax apply to all my income?
It applies to net earnings from self-employment, meaning business income after deducting business expenses. It does not apply to investment income, interest, dividends, capital gains, or most rental income. The Social Security portion applies only up to an annual wage base limit, above which only the Medicare portion continues, and an additional Medicare surtax applies above a higher threshold. This is why effective rates fall somewhat at higher incomes.
What happens if I just pay everything in April?
You will owe an underpayment penalty, calculated as interest on each period's shortfall for the time it was outstanding. It is not usually catastrophic on modest amounts, but it is entirely avoidable and it compounds if it becomes a habit. The larger practical risk is behavioural: a single annual bill of $21,230 is far harder to produce than four payments of $5,307.50, and people who have not set the money aside often cannot pay it.
Disclaimer: This article is educational and does not constitute financial, investment, tax, or legal advice. Figures are illustrative and computed from the assumptions stated in the article; your own situation will differ. Verify any decision with a qualified professional before acting on it.