What this calculation measures
Basal metabolic rate is the energy needed for vital functions under strict resting conditions. Mifflin-St Jeor more specifically estimates resting energy expenditure, a related measure commonly labelled BMR in calculators.
The Mifflin-St Jeor equation
Using weight in kg, height in cm and age in years: 10 × weight + 6.25 × height − 5 × age. Add 5 for males, or subtract 161 for females. Sex selects the coefficient from the original equation.
Worked examples, not intake targets
At age 30 and height 170 cm, a 65 kg woman has an estimated resting expenditure of 1,402 kcal/day; a 75 kg man, 1,668 kcal/day. These examples are estimates at rest, not recommended intakes.
BMR vs TDEE: what is the difference?
TDEE is total daily energy expenditure. It includes rest, movement, exercise and digestion. Our TDEE calculator adds an activity estimate: use it to approximate maintenance calories.
Estimate my daily energy needs →Frequently asked questions
How accurate is the estimate?
An equation is a starting point, not an individual measurement. Body composition and health can affect actual expenditure. The original study included 498 adults aged 19–78; this tool stays within that age range. Indirect calorimetry can measure resting expenditure.
Can I use my BMR to lose weight?
BMR alone cannot set a food intake or deficit: estimate total expenditure first. This number is neither an intake target nor a universal safety threshold. Pregnancy, breastfeeding and medical conditions call for appropriate individual guidance.
Why is my weight not in the address?
The calculation runs in your browser. This form does not save your profile or put body measurements in the URL. Website usage events do not include the values you enter.
Sources and method
Mifflin MD, St Jeor ST, et al. (1990). A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 51(2):241–247.Turn the calculation into a daily food log.
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