Paycheck Calculator

def calculate_paycheck(
    gross_annual: float,
    filing_status: str = "single",
    state_tax_rate: float = 0.05,
    k401_pct: float = 0.06,
    health_ins: float = 200,
    hsa: float = 50,
    pay_periods: int = 26
) -> dict:
    gross = gross_annual / pay_periods
    pretax_deductions = gross * k401_pct + health_ins + hsa

    # 2024 federal tax brackets (single)
    brackets_single = [
        (11600, 0.10), (44725, 0.12), (95375, 0.22),
        (201050, 0.24), (383900, 0.32), (487450, 0.35), (float('inf'), 0.37)
    ]
    brackets_married = [
        (23200, 0.10), (89450, 0.12), (190750, 0.22),
        (364200, 0.24), (462500, 0.32), (693750, 0.35), (float('inf'), 0.37)
    ]
    brackets = brackets_married if filing_status == "married" else brackets_single

    taxable_annual = gross_annual - (pretax_deductions * pay_periods)
    fed_tax_annual = 0
    prev = 0
    for limit, rate in brackets:
        if taxable_annual <= prev:
            break
        fed_tax_annual += min(taxable_annual, limit) * rate - prev * rate
        prev = limit
    federal_tax = fed_tax_annual / pay_periods

    ss_tax = min(gross, 168600 / pay_periods) * 0.062
    medicare_tax = gross * 0.0145
    state_tax = gross * state_tax_rate
    total_deductions = pretax_deductions + federal_tax + ss_tax + medicare_tax + state_tax
    net = gross - total_deductions

    return {
        "gross": round(gross, 2),
        "federal_tax": round(federal_tax, 2),
        "social_security": round(ss_tax, 2),
        "medicare": round(medicare_tax, 2),
        "state_tax": round(state_tax, 2),
        "pretax_deductions": round(pretax_deductions, 2),
        "net": round(net, 2)
    }

result = calculate_paycheck(75000, "single", 0.05, 0.06, 200, 50, 26)
print(f"Gross:    ${result['gross']:,.2f}")
print(f"Net Pay:  ${result['net']:,.2f}")