BMR & TDEE Calculator

Estimate adult BMR and TDEE from the Mifflin-St Jeor equation and an explicit activity multiplier.

Adult planning estimate only. Not suitable for children, pregnancy, diagnosis, treatment, or an individualized calorie prescription. Consult a qualified clinician or dietitian for medical or nutrition decisions.

Results will appear here.

Adult screening estimate only, not a diagnosis. Body composition, age, pregnancy, medical history, and population-specific risk can change interpretation; discuss health decisions with a qualified clinician.

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How this calculator works

Reviewed July 2026

Formula

Mifflin–St Jeor adult resting energy estimate: 10 × weight kg + 6.25 × height cm − 5 × age + sex term (+5 male, −161 female). TDEE multiplies estimated BMR by the selected activity factor.

Worked example

For a 30-year-old male equation term at 80 kg and 180 cm, estimated BMR is 1,780 kcal/day; a 1.2 activity factor gives about 2,136 kcal/day TDEE.

Assumptions to verify

  • The equation is limited to adults age 18–100 in this tool.
  • Activity multipliers are rough population planning categories, not measured expenditure.
  • Pregnancy, illness, medications, body composition, adaptive metabolism, and clinical conditions are not modeled.

Frequently asked questions

Is TDEE a calorie prescription?

No. It is a planning estimate and can differ substantially from measured individual needs.

Why does the equation ask for a sex term?

The published equation contains sex-specific constants; this tool labels that mathematical input explicitly.

Who should not use this estimate alone?

Children, pregnant people, people with medical conditions, and anyone making clinical nutrition decisions should seek qualified guidance.

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