Iowa paycheck calculator

The official method, step by step

• Pay is annualized, then reduced by the Form W-4 amount for your filing status ($8,600, or $12,900 if married filing jointly) unless the Step 2 box is checked.
• Federal income tax comes from the IRS 2026 Annual Percentage Method table for that status, divided back to one paycheck.
• Social security is 6.2% of wages until the year's wages reach $184,500.
• Medicare is 1.45% of all wages, plus 0.9% on wages over $200,000 in the year.
• A pre-tax 401(k) lowers federal income tax wages, not social security or Medicare wages.
• Iowa income tax follows the Iowa Withholding Formula effective 1 January 2026: the pay period's deduction for the IA W-4 marital status comes off ($500 every two weeks for most employees, $750 for head of household, $1,000 for married filing jointly with a spouse who has no earned income), 3.80% applies, and the IA W-4 allowance amount divided over the pay periods is subtracted.

What this leaves out

• IA W-4 forms from 2023 or earlier, which use allowance counts
• IA W-4 additional withholding (the pay stub generator handles it)
• Benefits, garnishments and other after-tax deductions
• W-4 Step 3 credits and Step 4 entries (the pay stub generator handles them)

Sources: Iowa Department of Revenue, Iowa Withholding Formula Effective January 1, 2026: deduction by marital status, 3.80%, less the IA W-4 allowance amount ÷ pay periods; Iowa Department of Revenue, 2026 IA W-4 Employee Withholding Allowance Certificate; IRS Publication 15-T (2026), Federal Income Tax Withholding Methods: Worksheet 1A and the Annual Percentage Method Tables; IRS Publication 15 (2026), (Circular E) Employer's Tax Guide: social security and Medicare tax, Additional Medicare Tax.