https://paychecksum.com/guides/section/methodology/Guides filed under Methodology on PaycheckSum: payroll taxes explained from primary sources.https://paychecksum.com/guides/methodology-employee-paycheck/https://paychecksum.com/guides/methodology-employee-paycheck/Mon, 26 Oct 2026 00:00:00 +0000Pub. 15-T federal withholding, annualized state tax, cumulative FICA, §224 flow-through, state data statushttps://paychecksum.com/guides/methodology-employer-cost/https://paychecksum.com/guides/methodology-employer-cost/Mon, 26 Oct 2026 00:00:00 +0000SUTA rates, FUTA credit status, workers' comp ranges, benefits assumptionshttps://paychecksum.com/guides/methodology-self-employment-tax/https://paychecksum.com/guides/methodology-self-employment-tax/Mon, 26 Oct 2026 00:00:00 +0000SE tax, half-SE deduction, simplified QBI, quarterly installments