$90,420/yr
take-home on a $120,000 salary in South Dakota — after $0 state income tax (0%) and $29,580 federal + FICA.
The breakdown
$120,000 × ~17% federal effective + 7.65% FICA = $29,580 federal/payroll
+ $0 SD state income tax (0%, No state income tax)
= $90,420/yr after tax
· Tax Foundation, “State Individual Income Tax Rates and Brackets, 2025” + state revenue departments. Modeled as an effective planning rate for a typical $80k–$160k filer — not a full bracket engine.