Paycheck Withholding Estimator (IRS Pub 15-T 2026)

Paycheck withholding combines three unrelated taxes (federal income tax, Social Security, Medicare) with different rules, and the federal income tax portion depends on projected annual income rather than the single paycheck in front of you. This estimator runs the IRS Publication 15-T "Percentage Method for Automated Payroll Systems" (Worksheet 1A) against the 2026 Annual Percentage Method tables: it annualizes the gross, looks up the tentative annual tax in the table for your filing status and W-4 Step 2 checkbox, and divides by pay periods to get per-period federal withholding.

Enter gross pay for a single period, pay frequency, filing status, whether the W-4 Step 2 box is checked (for a second job or working spouse), and year-to-date wages so the Social Security wage base cap and the Additional Medicare Tax threshold apply correctly on paychecks near those lines. The result shows federal income tax withheld, Social Security (6.2% up to the $184,500 wage base for 2026), Medicare (1.45% on all wages, plus 0.9% on wages over $200,000 year-to-date), and estimated net pay.

This is an estimate, not a tax filing. The W-4 has four additional adjustment steps (Step 3 credits for dependents, Step 4(a) other income, Step 4(b) deductions above standard, Step 4(c) extra withholding) that can each change the number and that this tool does not model. State and local taxes are also excluded because 40+ separate state tax regimes would require a state-by-state tool. For the exact paycheck number, use the IRS Tax Withholding Estimator at irs.gov, licensed payroll software, or a CPA. See the editorial standards for when a tool is a reference aid versus a filing-grade calculation.

Federal income tax: annualize gross (per-period × pay periods per year), then look up the Adjusted Annual Wage Amount in the IRS Publication 15-T 2026 Percentage Method Annual Tables (Worksheet 1A) for the selected filing status and W-4 Step 2(c) checkbox state. Each bracket row defines tax = base + (wage - bracketMin) × rate. The annual tax divides back by pay periods to get per-period federal withholding. The table breakpoints reflect the 2026 inflation adjustments published in IRS Rev. Proc. 2025-32; the MFJ Step 2 unchecked table starts the 10% bracket at $19,300, and the Single Step 2 unchecked table starts at $7,500.

Social Security: 6.2% of gross wages up to the 2026 annual wage base of $184,500 per IRS Publication 15 Circular E (For use in 2026). Once year-to-date wages reach the wage base, no further Social Security is withheld for the rest of the calendar year. The tool takes YTD wages as an input so a paycheck crossing the cap withholds only on the remaining room.

Medicare: 1.45% of all wages with no wage-base cap.

Additional Medicare Tax: 0.9% on wages paid to an employee in excess of $200,000 year-to-date per Pub 15. The employer withholds this once YTD crosses $200,000 regardless of filing status; the employee reconciles their actual liability (with filing-status-based thresholds of $200,000 single, $250,000 MFJ, $125,000 MFS) on Form 1040 when filing.

Use this to sanity-check a new paycheck, estimate take-home on a salary offer, or project net pay when modeling a raise or a change in pay frequency. For anything that hits a tax return, use licensed tax software or a CPA. For state tax, use your state's published withholding table. For a bonus paycheck where supplemental wage withholding rules apply (flat 22% up to $1 million, 37% above, or the aggregate method), this calculator will overstate the bonus's withholding because it uses the regular Percentage Method. For a mid-year W-4 change where the employee claims dependents, other income, or extra withholding, this tool does not model those adjustments; the IRS Tax Withholding Estimator at irs.gov is the official tool for that. Pair with the overtime calculator when projecting weeks that include overtime hours.