1099 vs W-2: how much to set aside for tax
Contractors do not get a W-2 withholding. Self-employment tax plus income tax is why 30% is a rumor, not a rule.
“Set aside 30%” is the advice every new 1099 contractor hears. Sometimes it is enough. In a high-tax state with a fat profit year it is short. On a low-profit year it is too much sitting in a savings account. The right number is self-employment tax plus estimated federal and state income tax, divided by net profit after expenses.
W-2 already took the money
On a W-2 job, payroll withholds federal income tax, Social Security, and Medicare before you see the deposit. The employer also pays a matching FICA amount you never see. You still file a return, but most of the year’s tax already left the paycheck.
On 1099-NEC or Schedule C profit, nobody withholds unless you asked a payer to. April feels like a surprise only because the money stayed in your operating account all year. The IRS still wants estimated tax during the year (Form 1040-ES).
Self-employment tax is the extra 15.3%
SE tax is 12.4% Social Security plus 2.9% Medicare, applied to 92.35% of net earnings from self-employment if net is at least $400. That 15.3% is both the employee and employer halves. Social Security stops at the same wage base as W-2. Extra 0.9% Medicare applies above $200,000 single or $250,000 joint.
Half of the 15.3% SE tax is deducted before you compute income tax. The calculator does that. It does not apply QBI, retirement, health insurance, or home-office deductions. Those shrink the income-tax slice. If you have them, our set-aside is a ceiling, not a floor.
Why 30% fails in both directions
SE tax alone is already about 14% of net after the 92.35% haircut. Federal income tax on top of that depends on filing status and the standard deduction. A single contractor at $40,000 net in Texas might land near the mid-20s as a percent of net. The same person at $180,000 in California can need well over 35% once state tax is in.
The 1099 page prints the percent it actually computed, plus an equal quarterly amount (annual tax ÷ 4). That quarterly figure is not a finished 1040-ES voucher. Safe harbor is 90% of this year’s tax or 100%/110% of last year’s tax. Due dates live on the IRS form.
Worked $80,000 net, single, on 2026-09-21: Texas self-employment tax $11,303.64, federal $7,526.60, total $18,830.24, leftover $61,169.76, set-aside 23.5%, quarter $4,707.56. California on the same profit: state $5,417.08, total $24,247.32, leftover $55,752.68, set-aside 30.3%, quarter $6,061.83. Thirty percent matches California here and overshoots Texas. Copy the percent the page prints, not the rumor.
Expenses come out first
Enter net profit after ordinary and necessary expenses, not gross invoices. Software, contractor labor, and a dedicated phone can be real. Meals and commuting are where people invent deductions they cannot defend. If you are unsure, run the calculator on a conservative net (higher profit) so you do not under-save.
Mixing W-2 and 1099
A lot of people have a day job and a side 1099. W-2 withholding might cover the job and still leave the side profit naked. The paycheck calculator and the 1099 calculator are separate on purpose. Add the two leftovers only after you understand each stack. One W-4 extra-withholding line can cover a small side gig. A larger gig needs its own quarterly.
Open the 1099 take-home calculator with net profit, status, and state. Then compare the same household on the W-2 paycheck calculator if you also have a salary. IRS publications on SE tax and 1040-ES win if the two disagree.
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