Tax Withholding Calculator

Your W-4 decides how much federal income tax comes out of every paycheck — and most withholding surprises trace back to four levers that are easy to confuse. This calculator models all four (Step 3, 4a, 4b, 4c) with their units labeled on every field, includes a two-jobs mode, a bonus true-up mode, and a translator for pre-2020 language like "claiming 0." It is free, runs entirely in your browser, shows the full formula, and replays identically from a saved snapshot URL — no account, no email, no payroll data leaving your device.

Step 3 — Dependents / other credits (annual amount). This reduces withholding, directly: the IRS treats each dollar here as a dollar of expected credit. Community-documented example: after a bonus was over-withheld, a filer trued up by entering $100 in Step 3. Unit: per year.

Step 4a — Other income (annual amount). Interest, side income not subject to withholding, and similar items that will be taxed but never passes through a payroll system. Entering it here raises withholding spread across the year. Unit: per year.

Step 4b — Deductions (annual amount). Only the amount by which your expected itemized deductions exceed your standard deduction belongs here — not the full itemized total. Unit: per year.

Step 4c — Extra withholding (per paycheck). The most powerful and most misused lever. Every dollar here comes out of each individual paycheck — not per year. Entering $100 here removes $100 × pay frequency per year ($2,600 if you are paid biweekly). Community threads are full of people who meant to add $100 per year and accidentally added $2,600. Unit: per paycheck — always.

Filing status and the two-jobs checkbox. Checking the two-jobs box tells payroll to withhold at roughly the single/married-half rate instead of the full married rate — the difference between a balanced year and an April surprise for dual-income households. The older Multiple Jobs Worksheet gives similar results but is only accurate if filled at year start; a mid-year job change breaks it, which is why this calculator projects from your actual pay stub year-to-date instead.

Pay frequency and YTD figures. Enter what's already been withheld this year from box 2 plus your YTD wages; the calculator projects the remaining pay periods so a mid-course correction is based on reality, not a January worksheet.

Bonus mode. Bonuses are typically withheld at a flat 22%. This mode computes the gap between 22% and your marginal rate — over-withheld (lower bracket) or under-withheld (24%+ bracket) — and suggests a concrete Step 3 or 4c amount to flatten it. Community-documented scale: high earners in the 24% bracket often need only tiny per-paycheck 4c amounts (a dollar per check) to true up.

Legacy language translator (pre-2020 W-4). Since 2020 the W-4 has no allowances at all — but "claiming 0," "claiming 1," and "15 allowances" still circulate widely, and some calculators even output allowance counts, which no longer map to anything. Type the old phrase and the translator returns the equivalent 2020+ settings: "claiming 0" ≈ withhold at the single/no-adjustments default (maximize); old child allowances converted at the historical roughly 4/2/1-per-child pattern depending on income level, restated as Step 3 dollars.

1. Project annual wages = YTD wages + (per-pay period wages × remaining paychecks).
2. Estimate annual federal income tax from brackets and credits (status + Step 3).
3. Add 4a income, subtract the 4b deduction excess, apply the two-jobs rate branch.
4. Target withholding per paycheck = (annual tax − expected credits − YTD withheld) ÷ remaining paychecks, plus 4c per paycheck.
5. Result: per-paycheck withholding to request on your W-4, plus a plain-English summary of what changes.

• Bracket tables per year (2023–2026); 2026 thresholds pending IRS first-hand verification, stamped in the constant-check module.
• Bonus flat withholding rate: 22% (supplemental wages).
• Sources: IRS Publication 505; Form W-4 instructions; annual revenue procedures.

This calculator produces an estimate for planning purposes. It is not tax advice, and it is not a substitute for filing an accurate return.

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