Payroll Tax Withholding (Simplified)
Federal income tax (Pub 15-T percentage method), employee FICA, Additional Medicare.
Example
You enter
- Gross wages this period (USD) 1500
- Pay frequency biweekly
- Filing status single
- Tax year 2025
You get
- Annual gross 39000
- Federal income tax this period $103.69
- Fed income tax annual 2696
- Social Security this period $93
- Medicare this period $21.75
- Total employee deduction $218.44
Details, formula, and sources
Single-filer brackets bundled.
Annualize gross. Apply Pub 15-T percentage-method bracket: fed_annual = base + (annual_gross - prev) * rate. Divide by pay periods. FICA: SS = min(gross, wage_base - ytd) * 0.062. Medicare = gross * 0.0145. Additional Medicare = 0.9% above the threshold.
IRS Publication 15-T, 2025 brackets bundled, Worksheet 1A (Percentage Method, manual payroll). Single-filer only.
Free at irs.gov/publications/p15t.
Estimate only. Tax law changes. Confirm with the current IRS publication or a licensed CPA before filing.
Field names used by the API: gross_per_period, pay_frequency, filing_status, tax_year, annual_gross, fed_income_tax_period, fed_income_tax_annual, ss_tax_period, medicare_period, total_employee_period
- Filer type single (illustrative)Pub 15-T Worksheet 1A
- Standard deduction baked into the bundled bracket startsPub 15-T 2025 percentage-method table