About this calculator
This BMR calculator estimates resting energy needs with the Mifflin-St Jeor equation. It is useful for nutrition planning, TDEE estimation, and comparing calorie targets.
Predictive equations are estimates. Actual energy expenditure can differ with body composition, illness, medications, training status, pregnancy, and metabolic adaptation.
Uses the Mifflin-St Jeor resting metabolic rate equation for adults: men = 10W + 6.25H − 5A + 5; women = 10W + 6.25H − 5A − 161, where W is kg, H is cm, and A is age in years.
Activated — resting energy estimate
Educational estimate only; not a diagnosis, prescription, or treatment plan.
Formula and method
Mifflin-St Jeor: male RMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5. Female RMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161.
Limitations and when not to rely on this result
- Educational estimate only; not a diagnosis, prescription, or treatment plan.
- Result depends on accurate inputs and may not apply to complex medical situations.
- Use clinician judgment, local guidance, and urgent care pathways when symptoms are severe.
Frequently asked questions
Is BMR the same as TDEE? +
No. BMR/RMR estimates resting energy needs. TDEE adds activity and daily movement on top of resting needs.
Is Mifflin-St Jeor accurate? +
It is a widely used predictive equation and often performs well compared with other common equations, but individual results can vary.
Can I use this during pregnancy? +
Pregnancy and lactation change energy needs. Use this only as background information and follow obstetric or dietitian guidance.
Why does sex change the result? +
The original equation uses different constants for male and female equations because average body composition differs between groups.
Should I eat exactly my BMR? +
Not necessarily. BMR is not a diet prescription. Daily calorie needs depend on activity, health goals, and medical context.