Gross-to-Net Payroll Calculator (FICA)

Gross-to-net payroll calculation: FICA (Social Security 6.2% up to the OASDI contribution and benefit base for the selected tax year, Medicare 1.45% uncapped, Additional Medicare Tax 0.9% on cumulative wages over $200,000 per IRC 3101(b)(2)), pretax deduction ordering (401(k)/HSA/Section 125 reduce both FICA and federal-taxable wages), and net pay. tax_year is a required input and selects the wage base: $184,500 for 2026 and $176,100 for 2025, with an absent or unsupported year failing closed with error unsupported_or_missing_tax_year rather than defaulting. The Social Security and Medicare rates and the $200,000 Additional Medicare threshold are statutory and not indexed, so they are not year-keyed. federal_withholding_per_period is a declared input, normally fed from art-338-compute-federal-withholding's output at the same tax_year, since kernels cannot import one another. Federal only, not tax advice, state withholding and state payroll taxes out of scope. Consumes art-338-compute-federal-withholding. Not compute_federal_withholding itself, which only computes the federal income tax withholding line.

Tool URL: https://ainumbers.co/chaingraph/art-339-compute-gross-to-net.html