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

instrument / verified-clean

# Metabolic Equivalent (MET) / Activity Energy Calculator

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Inspectable records

[01**Overview**Purpose and lifecycle](<https://guthlabs.ai/docs/instruments/metabolic-equivalent-met-activity-energy-calculator/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/metabolic-equivalent-met-activity-energy-calculator/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/metabolic-equivalent-met-activity-energy-calculator/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/metabolic-equivalent-met-activity-energy-calculator/qualification/>)

## Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

**Area**: Biology, Medicine & Pharmacology (educational estimates only — every panel labeled not-medical-advice)

**Tranche**: tranche-7

**Evidence ID**: t7-071

**Ledger rows**: 1

No ledger note is attached.

## Review findings

The core formula is standard for gross energy expenditure, but the instrument needs an explicit duration unit, a versioned MET lookup convention, input constraints, and an honest gross-versus-net label. The fourth test vector is deliberately corrected in its working: 8.0 × 3.5 × 75 / 200 = 10.5 kcal/min, so 1 hour produces 630 kcal.

### Formula and scope findings

- The formula kcal/min = MET × 3.5 × weight(kg) / 200 is the standard population-average estimate for gross energy expenditure, assuming 1 MET = 3.5 mL O2/kg/min and approximately 5 kcal/L O2.

- The specification does not state whether the result is gross calories or net/active calories. Net expenditure is commonly estimated as (MET - 1) × 3.5 × weight(kg) / 200, so the output label must explicitly say gross or net.

- The duration unit is unspecified. Because the formula produces kcal/min, duration must be explicitly supplied or converted to minutes.

- The activity-MET lookup and activity-name mapping are unspecified; the instrument needs a defined Compendium table version and behavior for activities absent from the table.

### Unit assumptions

- MET is dimensionless and represents the activity's gross metabolic rate relative to resting metabolism.

- Weight is body mass in kilograms.

- The formula output is kilocalories per minute.

- Duration is converted to minutes before multiplication; one hour equals 60 minutes.

- The 3.5 mL O2/kg/min MET convention and approximately 5 kcal per liter of oxygen convention are assumed.

- Expected outputs below are gross kcal, not net active kcal.

## Boundary hardening

**BREAK_CLAIMED** · SELF_FLAGGED

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.

## Errata and corrections

No applied erratum is attached to this unique-name record.

## Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

````
{
  "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."
}
````

## Related workflows

No source-defined multi-instrument workflow membership is recorded.

## Sources and evidence

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

- `VERIFIED_LEDGER.json · VERIFIED_CLEAN`

- `evidence-tranche7/tranche7-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`