Reconstruct the Activity You Actually Completed
- Match the full description or document a custom MET
Choose by speed, workload, surface, and activity wording—not by the broad category that sounds most flattering. A brisk level walk and a slow walk have different codes. If no curated row fits, record the source for a custom MET and confirm that its activity, intensity, and population match the interval.
- Count active interval time honestly
Use the duration represented by the selected activity. Long rests during resistance training or stops during a trip can make clock time a poor stand-in for continuous work.
- Enter current body weight
The standard equation scales with kilograms. Pounds are normalized before calculation; that conversion does not personalize the population MET value.
Audit the Formula Before Comparing Calorie Expenditure
The convention selector changes a constant, not the activity code, entered person, or duration. Keep the choice visible whenever you compare or publish a result.
Oxygen-reference convention
Gross kcal equals MET × kilograms × minutes × 3.5 ÷ 200. Over one hour this is 1.05 × MET × kilograms, so the method retains the standardized 3.5 mL O₂/kg/min reference.
Compendium approximation
Gross kcal approximately equals MET × kilograms × hours. For identical inputs this implementation is exactly 5% lower than the oxygen-reference result; the simpler value is not silently averaged with it.
Reproducible calculation record
Save the activity code or custom-MET source, complete description, body-weight date, duration and unit, and selected convention. Then confirm that gross energy equals the one-MET reference component plus the amount above reference rest before comparing records.
Read Gross Burn and Above-Rest Burn as Different Bookkeeping Views
Gross activity energy
Gross energy includes the one-standard-MET reference component that would exist during the same interval. Many consumer displays call this total calories.
Above-reference-rest energy
This subtracts exactly one standardized MET. It is not the same as subtracting your measured resting metabolism, and it may differ from a watch's proprietary “active calories.”
Walking-step reconstruction
When the source record is a step count rather than a timed session, the steps-to-calories calculator first derives distance and time from measured step length and walking speed.
Use a Workout Log to Explain Changes Instead of Chasing Exactness
For repeated sessions, keep activity code, convention, weight, duration, terrain notes, and equipment settings consistent. Then the estimate can support within-method comparisons. A higher value after a longer session reflects the equation's inputs; it does not prove an equivalent physiological adaptation or establish how much body fat changed.
Strength work illustrates the distinction. The Compendium supplies population MET values for categories such as vigorous resistance training, while the 1RM estimator answers a load-and-repetition question. Neither number substitutes for the other, and neither designs an individualized program.
Avoid Common Post-Workout Accounting Errors
- One recorded interval is not TDEE: it omits basal metabolism, food thermogenesis, and movement outside the selected activity. Do not add its gross result to a daily expenditure estimate that already represents the activity, because that can count the same movement twice. Use the TDEE estimator only for its separate complete-day planning task.
- Do not subtract the result from food intake and call the remainder a diagnosis of energy availability. Nutrition and recovery require broader assessment.
- If comparing intake with total expenditure, use the calorie-gap calculator and preserve its dynamic-weight warning; a session estimate does not predict pounds lost.
- Youth, adults over 59, pregnancy, disability, significant illness, and conditions affecting metabolism fall outside the core 2024 adult Compendium scope and may need different evidence.
Know Why Two Devices Can Disagree After the Same Session
A standard MET represents a reference energy cost, commonly anchored to 3.5 mL oxygen per kilogram per minute. Real resting metabolism and activity efficiency vary with age, fitness, body composition, environment, technique, and health. Wearables may combine heart rate, motion, proprietary models, and device-specific definitions, so agreement is not expected. When recording the estimate, name the selected convention and avoid precision that the population model cannot support.
This calculator does not measure oxygen consumption, post-exercise energy use, heat stress, or compensatory movement later in the day. Stop exercise and seek appropriate help for chest pain, fainting, severe breathlessness, or other concerning symptoms. The estimate is suitable for transparent activity logging, not diagnosis, medical clearance, or individualized calorie prescription.