Form W-4 · Step 2(b) · Extra withholding
The one number to put on Line 4(c) when you work two jobs
Two jobs? Your employers each withhold like the other doesn’t exist — which is why you owe in April. Here’s the single dollar figure for Line 4(c) of one W-4 to fix it, without telling either employer about the other.
Enter both annual salaries — we sort them and read the right table for you.
Spread the annual amount over the pay periods left this year instead of a full year — the same proration Pub. 505 uses so you’re not catching up over too few checks.
How it works
Why two jobs under-withhold — and what Line 4(c) fixes
Withholding assumes the paycheck in front of it is your only income. Each employer applies the full standard deduction and starts you in the lowest tax brackets. That’s correct for one job. Add a second, and both employers are quietly doing the same thing — so your combined income gets the standard deduction and the low brackets counted twice, when in reality it stacks into higher brackets. Neither employer knows about the other. The shortfall shows up as a balance due in April.
What “Line 4(c)” actually is
On the W-4, Step 4(c) is labeled “Extra withholding.” It’s a single dollar amount of additional federal tax your employer pulls from each paycheck, on top of the normal calculation. It’s the one lever on the form that directly adds dollars — no allowances, no guessing. The whole job here is figuring out the right number to write in that one box.
The worksheet behind the number — Step 2(b), Table 1
The IRS already solves the two-job problem on paper: the Multiple Jobs Worksheet (Step 2(b)) reads Table 1 on page 5 of the 2026 Form W-4. You find your higher salary down the left, your lower salary across the top, and the cell where they meet is an annual additional-withholding amount. That grid is public — but it only gives you a yearly figure.
The part people get wrong: the per-paycheck division
The number you write on Line 4(c) isn’t the annual figure — it’s that figure divided by your pay periods. Do it by hand and it’s easy to divide by the wrong count, or to use a full year when you’re actually filing in June with far fewer checks left. This calculator does both: the standard full-year division, or — if you flip the mid-year switch — the proration over the pay periods remaining this year, which is exactly what IRS Pub. 505 tells you to do when you adjust withholding partway through the year.
When to skip this and use the IRS estimator instead
Table 1 is built for exactly two jobs (or two earners filing jointly). Use the IRS Tax Withholding Estimator instead if you have three or more jobs, if more than one job pays over $120,000, or if you have big swings like bonuses, equity, or self-employment income. This tool deliberately does the one worksheet path — not the whole estimator.
FAQ
Two-job withholding, answered
What do I put on Line 4(c) of the W-4?+
A single dollar amount of extra federal tax to withhold each paycheck. For two jobs, it’s the annual Table 1 figure from the Multiple Jobs Worksheet divided by your pay periods — entered only on the W-4 for your higher-paying job.
How much extra should I withhold for a second job?+
Enter both salaries above. We read Table 1 for your filing status to get the annual amount, then divide by your pay periods (or the periods left this year) to give you the per-paycheck Line 4(c) figure.
Do I have to tell my employer about my second job?+
No. The figure goes on one W-4 — your higher-paying job’s. You don’t report your other income to either employer and you don’t submit the worksheet. Step 2(b) is built to keep that income private from your employer.
Why do I owe taxes when I have two jobs?+
Each employer withholds as if its paycheck is your only income — applying the standard deduction and lowest brackets to each job separately. Combined, your income stacks into higher brackets, so the two jobs under-withhold and you owe the gap. Line 4(c) closes it.
We’re married and both work — does this apply?+
Yes. For Table 1, a dual-income couple filing jointly is the same as one person with two jobs: combine the two incomes, look up higher and lower, and put the result on one spouse’s W-4 (the higher-paying job). Choose Married, joint above.
What if I have three or more jobs?+
Table 1 covers exactly two jobs. For three or more — or if more than one job pays over $120,000 — use the IRS Tax Withholding Estimator, which handles the multi-step path this tool doesn’t model.
Does this cover state tax or self-employment?+
No — federal Line 4(c) only; state forms differ. For 1099 or self-employment income, the W-4 can’t help; pay it as quarterly estimated tax instead.
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