Source: https://guthlabs.ai/docs/instruments/calories-burned-estimator-met-tables/mechanism/

instrument mechanism / verified-clean

# Calories Burned Estimator (MET Tables) mechanism

The inspectable method record for Calories Burned Estimator (MET Tables), kept separate from implementation and qualification.

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

## Model scope

The algorithm is standard for gross estimated energy expenditure, but the specification needs an explicit choice between gross kcal and active kcal, explicit kg/hour input units, and a defined Compendium table edition and activity-row matching policy. The existing population-average and not-medical-advice label is appropriate.

- calories = MET × weight_kg × duration_hr is the standard gross-energy estimate when MET is expressed as kcal/kg/hour.

- The formula is ambiguous about gross calories versus active calories. Gross energy uses MET × kg × hours; active calories above resting expenditure generally use (MET - 1) × kg × hours.

- The output should be labeled kilocalories (kcal), conventionally called food Calories (Cal), rather than simply calories.

## Units and conventions

- Body weight must be supplied in kilograms.

- Duration must be converted to decimal hours before applying the formula; for example, 45 minutes = 45/60 = 0.75 hours.

- MET is dimensionless but is interpreted using the standard approximation 1 MET = 1 kcal/kg/hour.

- The reported value is a population-average estimate and does not account for individual efficiency, body composition, fitness, age, environment, or activity execution.

## Inspectable vector

One of 4 source-bound review vectors:

````
{
  "inputs": {
    "activity": "Walking at 3.0 mph (4.8 km/h), level",
    "duration": 1.5,
    "duration_unit": "hours",
    "weight_kg": 80
  },
  "expected_outputs": {
    "estimated_energy_kcal_gross": 396
  },
  "reference_data": {
    "activity": "Walking at 3.0 mph, level",
    "MET": 3.3,
    "source_convention": "Ainsworth et al., Compendium of Physical Activities, 2011 update; widely tabulated standard value"
  },
  "working": "MET × weight × duration = 3.3 × 80 kg × 1.5 h = 264 × 1.5 = 396.0 kcal gross."
}
````

## Failure boundary

**BREAK_CLAIMED** · SELF_FLAGGED

The estimator has no division-by-zero formula trap, but an extreme valid-number input can overflow ordinary floating-point arithmetic to Infinity, and an unlabeled body-weight unit can change the estimate from 662.2 kcal to 300.3686224 kcal.

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/calories-burned-estimator-met-tables/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/calories-burned-estimator-met-tables/implementation/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/calories-burned-estimator-met-tables/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`

- `BOUNDARY_HAZARD_CATALOG.json`