Source: https://guthlabs.ai/docs/instruments/metabolic-equivalent-met-activity-energy-calculator/implementation/

instrument implementation / implementation-contract

# Metabolic Equivalent (MET) / Activity Energy Calculator implementation

A source-bound implementation contract for Metabolic Equivalent (MET) / Activity Energy Calculator; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## 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**: t7-071

**Effect**: Computation or source lookup only

## Input and validation requirements

The extreme-magnitude vector causes floating-point overflow, and the duration field has an unresolved unit ambiguity that can change the result from 183.75 kcal to 11025 kcal for the same numeric input.

## 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": {
    "activity": "Walking at 3.0 mph",
    "met": 3.5,
    "weight_kg": 70,
    "duration_min": 30
  },
  "expected_outputs": {
    "kcal_per_min": 4.2875,
    "total_kcal": 128.625
  },
  "reference_data": {
    "activity": "Walking, 3.0 mph",
    "met": 3.5,
    "source_convention": "widely tabulated standard value; Compendium of Physical Activities, 2011 update (Ainsworth et al.)"
  },
  "working": "MET × 3.5 × weight / 200 = 3.5 × 3.5 × 70 / 200. First, 3.5 × 3.5 = 12.25. Then 12.25 × 70 = 857.5. Then 857.5 / 200 = 4.2875 kcal/min. Total = 4.2875 × 30 = 128.625 kcal."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/metabolic-equivalent-met-activity-energy-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/metabolic-equivalent-met-activity-energy-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/metabolic-equivalent-met-activity-energy-calculator/qualification/>)

## 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`