Metabolic Age Calculator — evidence-based tool to check your metabolic age. Includes formula, tips, and interpretation guide.
Informational only — not a diagnosis. The Metabolic Age Calculator is an educational tool for a transparent, non-clinical metabolic-age estimate. It does not diagnose, rule out, or treat a condition, and it should not be used to start, stop, or change medicine. For related context, see BMI Calculator and Body Fat Calculator.
Use the page only with the units and context shown beside each field. chronological age, sex, height, weight, resting heart rate, weekly moderate activity, and typical sleep are not interchangeable with a different specimen, collection time, assay, device, or population. Preserve the date and original laboratory report, because an apparently precise comparison can still be wrong when a reference interval or method has changed.
There is no single accepted clinical definition of metabolic age. This page does not compare a person's metabolism with a validated population database; it reports a simplified index based on self-reported inputs so the assumptions remain visible. Body size, medication, illness, pregnancy, measurement error, training status, and changing routines can all alter the underlying values. A lower displayed estimate is not proof of better health, and a higher one is not evidence of disease. A qualified clinician should interpret an abnormal, unexpected, urgent, or personally concerning result with the symptoms, history, examination, medicines, and the laboratory's own range.
Mifflin–St Jeor BMR plus a clearly displayed lifestyle adjustment produces an illustrative age-equivalent estimate. The output is clamped to ages 18–90 so an extreme input does not create a misleadingly precise negative or implausible age.
Reference intervals describe the population and method used by a laboratory; they are not universal treatment thresholds. The reporting laboratory's interval normally takes priority over an example shown here. Age, sex, pregnancy, cycle phase, collection time, fasting status, assay calibration, medicines, and jurisdiction can all change what a result means.
For the named source behind this page, see Mifflin et al., American Journal of Clinical Nutrition, resting energy expenditure equation.The sources are provided so the assumptions can be checked, not so a web calculator can replace the ordering clinician or the laboratory report.
The result is best treated as a prompt to verify context. A value near a boundary can move between categories because of biological variation, rounding, collection conditions, device or assay differences, and the chosen reference population. Repeat testing, when clinically appropriate, should follow the clinician's instructions rather than an arbitrary schedule.
Body size, medication, illness, pregnancy, measurement error, training status, and changing routines can all alter the underlying values. A lower displayed estimate is not proof of better health, and a higher one is not evidence of disease. If symptoms are severe, rapidly worsening, or urgent, seek appropriate medical care instead of waiting for a calculator comparison. Do not infer a diagnosis from a normal-looking result, because a calculator cannot see symptoms, examination findings, medication history, or related laboratory values.
Informational only — not a diagnosis. Share the raw value, unit, collection date, reference interval, and relevant context with a qualified clinician. That information is more useful than reporting the category alone.
Informational only — not a diagnosis. This calculator is general educational information, not medical advice, a laboratory report, a diagnosis, a treatment recommendation, or an emergency service. Reference ranges and clinical practice vary by laboratory, assay, jurisdiction, age, sex, pregnancy, medicines, and patient history. Discuss results and care decisions with a qualified clinician.