How to Build a Take Home Calculator

function calculateTakeHome(grossAnnual, federalTax, stateTax, deductions = {}) {
  const socialSecurity = Math.min(grossAnnual, 168600) * 0.062;
  const medicare = grossAnnual * 0.0145;
  const fica = socialSecurity + medicare;

  const preTaxDeductions = (deductions.retirement || 0) +
                          (deductions.health || 0) +
                          (deductions.hsa || 0);

  const netAnnual = grossAnnual - federalTax - stateTax - fica - preTaxDeductions;

  return {
    gross: grossAnnual,
    federal: federalTax,
    state: stateTax,
    fica: fica,
    deductions: preTaxDeductions,
    net: netAnnual,
    monthly: netAnnual / 12,
    biweekly: netAnnual / 26
  };
}