Calculator guide
Estimate resting energy needs with the Mifflin–St Jeor equation and optionally scale them for activity.
Formula or method
BMR (men)=10W+6.25H−5A+5; BMR (women)=10W+6.25H−5A−161, with W kg, H cm, A years; TDEE≈BMR×activity factor.
How to use this calculator
- Enter weight, height, age, and selected sex-at-birth equation.
- Choose an activity factor if TDEE is shown.
- Use the result as a starting estimate and monitor real-world changes.
Worked example
For a 30-year-old woman, 65 kg and 165 cm: BMR=650+1031.25−150−161=1,370.25 kcal/day.
Understanding the result
BMR is resting energy expenditure; TDEE is a rough daily estimate including activity. Individual needs vary.
Limitations and assumptions
- Equations are population estimates and do not measure metabolism directly.
- Illness, pregnancy, body composition, exercise, and goals can change energy needs.
Frequently asked questions
Does BMR equal calories to eat?
No. It excludes normal daily movement and is not a personalized diet prescription.
Why ask sex at birth?
The selected equation uses different population coefficients; it is an estimate, not a judgment.
Should I change calories immediately?
Discuss nutrition changes with a qualified clinician or dietitian, especially with medical conditions.
Sources
Educational estimate only; not medical or nutritional advice.