Payroll / Employee Cost Calculator (Employer Side) implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t7-118

Effect

Computation or source lookup only

Input and validation requirements

A zero salary produces a valid total cost of zero but makes the cost multiplier 0/0, which is undefined. The instrument should reject that multiplier calculation or return an explicit undefined value. The overhead input also has a material percent-versus-decimal convention hazard.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "calendar_year": 2024,
    "base_salary_usd": 200000,
    "benefits_cost_usd": 30000,
    "employer_suta_rate": 0.027,
    "overhead_percent": 0.12
  },
  "expected_outputs": {
    "employer_social_security_usd": 10453.2,
    "employer_medicare_usd": 2900,
    "employer_fica_usd": 13353.2,
    "futa_usd": 42,
    "suta_usd": 189,
    "overhead_usd": 24000,
    "fully_loaded_annual_cost_usd": 267584.2,
    "cost_multiplier_on_salary": 1.337921
  },
  "reference_data": {
    "social_security_rate": 0.062,
    "social_security_wage_base_usd": 168600,
    "social_security_source_convention": "US Social Security Administration 2024 contribution and benefit base",
    "medicare_rate": 0.0145,
    "medicare_source_convention": "IRS/FICA standard employer Medicare tax rate",
    "futa_net_rate": 0.006,
    "futa_taxable_wage_base_usd": 7000,
    "futa_source_convention": "IRS standard FUTA rate after full 5.4% credit, assuming no credit reduction",
    "suta_rate": 0.027,
    "suta_taxable_wage_base_usd": 7000,
    "suta_source_convention": "Illustrative state unemployment-agency schedule; state is unspecified and 2.70% is not a universal standard"
  },
  "working": "Social Security = min(200000, 168600) x 0.062 = 168600 x 0.062 = 10453.2. Medicare = 200000 x 0.0145 = 2900.0. Employer FICA = 10453.2 + 2900.0 = 13353.2. FUTA = min(200000, 7000) x 0.006 = 7000 x 0.006 = 42.0. SUTA = min(200000, 7000) x 0.027 = 7000 x 0.027 = 189.0. Overhead = 200000 x 0.12 = 24000.0. Total = 200000 + 30000 + 13353.2 + 42.0 + 189.0 + 24000.0 = 267584.2. Multiplier = 267584.2 / 200000 = 1.337921."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche7/tranche7-results.json