BMR Calculator
Estimate resting energy expenditure using the simplified Mifflin–St Jeor equation and your adult age, height, weight and selected equation parameter.
Calculator arithmetic runs locally in your browser and does not require an API.
The interactive calculator loads here when JavaScript is enabled.
How to use BMR Calculator
Choose metric or imperial units, then re-enter measurements in those units. The equation uses male or female parameters and accepts adult ages; no activity level is applied here.
Formula and method
Estimated resting kcal/day = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) + s. The equation constant s is +5 for male parameters and −161 for female parameters.
Understanding the results
Although commonly labeled BMR, this formula estimates resting energy. It is not a measured metabolic rate or a recommended food intake, and it excludes activity, pregnancy, breastfeeding and illness.
Worked example
At age 40, height 165 cm and weight 60 kg using the female equation: 600 + 1,031.25 − 200 − 161 = 1,270.25 kcal/day of estimated resting energy.
Results are estimates for general information, not a diagnosis or a substitute for professional medical advice.
References
Frequently asked questions
Why is there no activity selector?
This page isolates the resting baseline. Calorie Calculator adds an activity multiplier.
Does this measure my metabolism?
No. It evaluates a predictive equation using the measurements you enter.
Should I eat exactly the displayed amount?
The result is not an intake recommendation; it represents estimated resting expenditure only.