How Much to Set Aside for Taxes on 1099 Income: 30% of Profit, Not Revenue.

A graphic designer quits a salaried job in March and starts taking contract work. By September the invoices total $120,000, and $30,000 of that went back out the door for software, a laptop, a subcontractor, and health insurance. Nothing was withheld from any of it, and no quarterly payment has gone out. The rule everybody repeats is to set aside 30%, and 30% of $120,000 is $36,000, which is not sitting in the account. How much to set aside for taxes on 1099 income really is about 30%. The number it gets applied to is the part people get wrong.

Schedule C net profit is gross receipts minus the ordinary and necessary business expenses of IRC §162. For the designer above that is $90,000, not $120,000. Reserving 30% of deposits puts $36,000 aside against a bill closer to $23,000 once state tax is in, and over-reserving by $13,000 sounds harmless right up until it is the reason a mortgage payment is late.

The opposite mistake is the expensive one. People set aside their income tax bracket, 12% or 22%, because that is the only rate they have ever had to think about, and they leave self-employment tax out entirely. Self-employment tax is the bigger half of the bill at most freelance income levels. In the example below it is $12,717 against $6,599 of income tax.

Two smaller things distort the profit figure. Money moved between your own accounts is not revenue, and a client reimbursement you reported as income and deducted as an expense nets to zero. Track the Schedule C line, not the bank balance.

Self-employment tax is 15.3% under IRC §1401: 12.4% for Social Security and 2.9% for Medicare. It does not run against your full profit. IRC §1402(a)(12) applies it to 92.35% of net earnings, so the effective rate on profit is 0.9235 times 15.3%, or 14.13%. That 14.13% is a floor. It ignores your filing status, your dependents, the standard deduction, and every deduction you found, because it is computed before all of them.

An employee splits those rates with an employer, 7.65% each. Working for yourself, you pay both sides. Half of what you pay comes back as an above-the-line deduction under IRC §164(f), which is real money against income tax and does nothing at all to the self-employment tax itself.

The Social Security piece stops. For 2026 the wage base is $184,500, so the 12.4% runs out there and profit above it carries Medicare only. Medicare never stops, and §1401(b)(2) adds 0.9% once self-employment income passes $200,000 single or $250,000 joint. The filing requirement starts far lower: IRC §6017 requires a return once net earnings from self-employment reach $400, whether or not a single 1099 ever shows up, and fewer of them will now that the reporting threshold has moved to $2,000.

30% is a reserve rule, and the rate underneath it moves. Run the same single filer at three profit levels on 2026 rates and the federal share comes out at 18.6% on $40,000, 21.5% on $90,000, and 25.1% on $150,000. The climb is the income tax brackets doing their work while self-employment tax sits flat at 14.13% the whole way.

State tax decides whether 30% holds. Up to roughly $150,000 of profit it covers the federal number plus a state in the 4% to 5% range with a little left over. Past $150,000, or anywhere in California or New York, make it 35%. A married filer whose spouse has W-2 wages should run real numbers instead of a percentage, because the spouse's bracket, not the profit, sets the rate on the last dollar.

What you set aside and what you owe by a given date are two different questions. IRC §6654 charges interest on each installment that came up short, quarter by quarter, and paying the whole balance on April 15 does not undo a September shortfall. The rate is 7% for the quarter that began July 1, 2026, and Rev. Rul. 2026-15 holds it at 7% for the quarter beginning October 1, compounded daily.

The safe harbor makes the projection unnecessary. Pay in, through estimates and withholding combined, either 90% of what you will owe for 2026, or 100% of your total 2025 tax if your 2025 AGI was $150,000 or less, or 110% of it if your 2025 AGI was higher. Section 6654(d)(1)(B) and (C) then shut off the penalty no matter what the year turns out to owe. The prior-year figure is line 24 of your 2025 Form 1040, and it is a number you already have, which is the whole appeal. Run it through the safe harbor calculator and divide by four.

The first year out of a W-2 job is where this bites. The safe harbor is measured against 2025 total tax, and a full salaried year generates a large one. The 2026 installments of April 15, June 15, September 15, and January 15, 2027 have to add up to that figure, and withholding from three months of salary in early 2026 will not get close. One exception is worth knowing: §6654(e)(1) waives the penalty outright if the tax still owed after withholding comes in under $1,000.

If you or a spouse still have wages, the fastest fix is not a check. Withholding counts as paid evenly across the year under §6654(g)(1) no matter which month it came out, so extra withholding on line 4(c) of a Form W-4 in October cures an underpayment dating back to April. An estimated payment counts only on the day you send it. The same arithmetic that covers a second W-2 covers a Schedule C.

A solo 401(k) is the largest one. For 2026 you can defer $24,500 as the employee and add an employer contribution on top, to a combined $72,000 under IRC §415(c). The old adoption deadline is gone for a first plan: section 317 of the SECURE 2.0 Act lets a sole proprietor with no employees adopt the plan as late as the unextended due date of the return, April 15, 2027 for tax year 2026, and still make that year's employee deferral. It works once, for the first plan year only. A SEP-IRA can be opened as late as the extended due date but has no employee deferral at all, so at the same profit it usually shelters less.

Health insurance you pay for yourself is deductible above the line under IRC §162(l), up to your net earnings from self-employment, with no need to itemize. And the Section 199A deduction is 20% of qualified business income, made permanent by P.L. 119-21 §70105. For 2026 the limits start at $201,750 of taxable income for a single filer and $403,500 joint, and a new $400 minimum deduction applies to anyone with at least $1,000 of qualified business income from a business they materially participate in.

None of these touch self-employment tax. They cut income tax only, which is why the 14.13% floor holds no matter how good the deductions get. The one structure that reduces self-employment tax is an S-corporation election, and it starts paying for itself somewhere north of $80,000 of profit, once you price out payroll, a second return, and a salary you can defend.