BMR Calculator
Estimate resting daily energy using the Mifflin-St Jeor equation. The original research describes a prediction of resting energy expenditure based on weight, height, age and a sex-specific constant. Online tools frequently label this type of estimate BMR. It remains a prediction rather than a direct measurement of an individual's metabolism.
Male equation: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5.
Female equation: 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161.
The original equation predicts resting energy expenditure. Online calculators commonly label this estimate BMR.
How to use the BMR Calculator
- Choose metric or US customary units and the sex-specific equation constant.
- Enter adult age, height and weight.
- US measurements are converted internally to kilograms and centimeters.
- For the male equation, the calculator uses 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5.
- For the female equation, it uses 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161.
- The result is shown in estimated kilocalories per day and an approximate hourly equivalent.
Examples
Male equation example
For 75 kg, 175 cm and age 35, the male equation is 10×75 + 6.25×175 − 5×35 + 5, giving an estimated resting expenditure of about 1,674 kcal/day.
Female equation example
The female equation uses the same weight, height and age terms but uses −161 as the final constant.
BMR versus total expenditure
A resting-energy estimate does not include a full day's activity. The TDEE Calculator applies an activity assumption to estimate total daily expenditure.
Frequently asked questions
What is BMR?
Basal metabolic rate commonly refers to energy required for basic body functions at rest. Predictive calculators estimate this from variables such as age, height and weight.
What is the Mifflin-St Jeor equation?
It is a published predictive equation developed from measured resting energy expenditure in adults and uses body weight, height, age and a sex-specific constant.
Is calculated BMR exact?
No. It is an estimate derived from a population equation and can differ from an individual's measured resting energy expenditure.
What is the difference between BMR and TDEE?
BMR or resting-energy estimates describe energy use at rest. TDEE additionally applies an activity assumption to estimate total daily expenditure.
Why does the equation ask for male or female?
The published Mifflin-St Jeor equation uses different constants for the two sex categories in the original predictive model. This is a limitation of the equation rather than a statement about gender identity.
Is this calculator for children?
No. QuickToolCenter limits this tool to adults and does not use it to estimate pediatric energy requirements.
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