Employed and Self-Employed Tax Calculator (W-2 + 1099)

Quick Answer: To estimate tax on combined W-2 and 1099 income, add your wages and your net self-employment profit, figure income tax on the total after deductions, then add self-employment tax on 92.35% of the 1099 profit. Your wages use up part of the Social Security wage base ($184,500 for 2026), so the 12.4% portion only applies to the room left. Subtract what your employer will withhold; the gap is what you cover with a bigger W-4 withholding or quarterly estimated payments.

When you have a salaried job and freelance income in the same year, your employer withholds tax as if the paycheck were your only income. The 1099 side has nothing withheld, and it carries self-employment tax on top of income tax. An employed and self-employed tax calculator has to combine both streams, because the two interact in the tax brackets and in the Social Security cap.

Why does a side business change the tax on your salary?

Three things happen when 1099 profit lands on top of a W-2 job:

• The side income is taxed at your top bracket. Your wages already fill the lower brackets, so every freelance dollar is taxed at the marginal rate your salary reached, or higher.
• Self-employment tax applies to the profit. The IRS sets the rate at 15.3%: 12.4% for Social Security and 2.9% for Medicare. It is figured on 92.35% of net earnings, and it applies once net self-employment earnings are $400 or more.
• Social Security stops at a combined cap. For 2026 the maximum amount of wages plus net self-employment earnings subject to Social Security tax is $184,500, per the 2026 Form 1040-ES instructions. Wages count first. If your salary is near or above the cap, the 12.4% part of self-employment tax shrinks or disappears, while the 2.9% Medicare part continues on all of it.

Two smaller adjustments sit alongside these. You deduct half of your self-employment tax (the employer-equivalent portion) when figuring adjusted gross income, and an extra 0.9% Additional Medicare Tax applies once combined wages and self-employment earnings exceed $200,000 for a single filer ($250,000 married filing jointly), as the IRS self-employment tax page explains.

The spreadsheet layout

Put inputs in column B and keep every rate in its own cell, so next year you change one number instead of hunting through formulas. This version is for a single filer taking the standard deduction; the 2026 Form 1040-ES lists $16,100 for that status.

Row 10 is the line generic calculators get wrong. (Strictly, income tax uses box 1 wages and the wage-base test uses box 3 Social Security wages; if pre-tax 401(k) contributions make them differ, add a row for each.) B5-B2 is the room left under the wage base after your salary; MAX(0,…) stops it going negative when wages exceed the base; MIN taxes whichever is smaller, the self-employment earnings or the room. This mirrors lines 5 to 9 of the self-employment worksheet in Form 1040-ES.

For row 15, the 2026 Schedule X (single) in Form 1040-ES gives the brackets. A nested formula that covers all seven:

=IF(B14<=12400,B14*0.1,
 IF(B14<=50400,1240+(B14-12400)*0.12,
 IF(B14<=105700,5800+(B14-50400)*0.22,
 IF(B14<=201775,17966+(B14-105700)*0.24,
 IF(B14<=256225,41024+(B14-201775)*0.32,
 IF(B14<=640600,58448+(B14-256225)*0.35,
 192979.25+(B14-640600)*0.37))))))

Paste it as one line in Excel or Google Sheets; the line breaks are only for reading. Married filers swap in the Schedule Y-1 thresholds and the joint standard deduction from the same form.

Worked example: $70,000 salary and $30,000 of freelance profit

Take a single filer earning $70,000 in wages who also cleared $30,000 from 1099 design work after expenses. Assume the employer's withholding is set correctly for the salary alone: about $6,570 for the year, the income tax on $70,000 less the standard deduction.

1. Net earnings for SE tax: $30,000 × 0.9235 = $27,705.
2. Medicare part: $27,705 × 2.9% = about $803.
3. Room under the wage base: $184,500 − $70,000 = $114,500, more than $27,705, so the full amount is taxed. Social Security part: $27,705 × 12.4% = about $3,435.
4. Self-employment tax: about $4,239. Half of it, $2,119, is deductible.
5. AGI: $70,000 + $30,000 − $2,119 = $97,881. Taxable income after the $16,100 standard deduction: $81,781.
6. Income tax: $5,800 + 22% × ($81,781 − $50,400) = about $12,704.
7. Total federal tax: $12,704 + $4,239 = about $16,943.
8. Shortfall after withholding: $16,943 − $6,570 = about $10,373.

So $30,000 of side profit added roughly $10,400 of federal tax, about 35% of it, which is why a first year of freelancing so often ends in a surprise bill. This simplified model leaves out the qualified business income deduction and any credits, both of which the 1040-ES worksheet includes, so a real return may come out lower.

How does a higher salary change the result?

Keep the $30,000 of freelance profit and change only the salary:

At $160,000 the wage base cuts the Social Security part, but the freelance income now sits in the 24% bracket, so the total added tax barely moves. At $190,000 the salary has already used the whole base, so self-employment tax falls to the Medicare part. That filer is also over the $200,000 Additional Medicare threshold on combined earnings, which adds about 0.9% on the portion above it; Form 8959 does that calculation on the return.

Should you raise W-4 withholding or pay estimated tax?

Both routes are legitimate. The IRS estimated taxes page says you generally must pay estimated tax if you expect to owe $1,000 or more when you file, and that you can instead ask your employer to withhold more by filing a new W-4.

Raising withholding. The 2026 Form W-4 handles this in Step 4(c), "Extra withholding", an amount per pay period. Its instructions tell you not to put self-employment income in Step 4(a), and point people with self-employment income to the IRS Tax Withholding Estimator to size the extra amount. In the example, $10,373 spread over 26 biweekly paychecks is about $399 each. Withholding is simple and automatic, and you do not need to track quarterly due dates.

Paying estimated tax. For 2026 the Form 1040-ES due dates are April 15, June 15 and September 15, 2026, and January 15, 2027. Quarterly payments suit you if the freelance income is lumpy or you do not want your employer's payroll involved. Our estimated tax payment tracker shows how to log what you sent and match it to your bank statement.

The penalty test either way. You generally avoid the underpayment penalty if withholding plus estimated payments cover at least 90% of this year's tax or 100% of last year's, whichever is smaller. Form 1040-ES raises the prior-year figure to 110% if last year's AGI was over $150,000 ($75,000 married filing separately).

Getting the 1099 number right

Row 4 is the input people guess at. It should be profit, not gross receipts: what clients paid you minus deductible business expenses. Forms 1099-NEC and 1099-K may not capture every payment, and they never show your costs, so build the figure from your business account instead. Export the year's statements to a spreadsheet, total deposits from clients, and subtract categorized expenses; the self-employed tax spreadsheet guide walks through categories. If the bank only gives you PDFs, QuickBankConvert can turn them into an Excel file with one row per transaction and money out shown as negative amounts, which makes the SUMIF totals straightforward.

If the 1099 work is your only income, the wage base and withholding questions fall away; the self-employed tax calculator spreadsheet is the simpler version of this sheet.

Related guides

• Organizing bank statements and 1099s for freelancer tax prep
• Choosing a tax accountant for a small business
• Year-end bank statement tax checklist

This sheet is an estimate for planning, not a substitute for the return or for advice on your situation.