Basal Metabolic
Rate Calculator
Discover your resting energy expenditure. Your BMR is the number of calories your body burns just to keep your organs functioning while at rest.
What Is BMR?
Basal Metabolic Rate (BMR) is the minimum amount of energy your body requires to function at rest. This includes breathing, circulating blood, controlling body temperature, cell growth, brain and nerve function, and contraction of muscles. Your BMR accounts for about 60% to 75% of the total calories you burn each day.
The Mifflin-St Jeor Equation
This calculator uses the Mifflin-St Jeor equation, which is currently considered the most accurate formula for estimating BMR in modern populations. It was developed in 1990 and has been validated as more reliable than the older Harris-Benedict formula.
Using the estimate well
Understanding Your Basal Metabolic Rate Result
Basal metabolic rate is an estimate of the energy your body uses at rest for functions such as breathing, circulation and temperature regulation. It is not the same as the calories used across a full day. Daily Meal Plan Healthy Formula applies the same idea to meal planning.
Online calculators simplify real life into a small number of inputs. Use this result as a transparent estimate that you can review, not as proof that a particular outcome will occur.
Enter consistent information
Enter current age, sex, height and weight in the requested units. Equations are based on population averages, so the output can differ from measured resting energy expenditure, especially when body composition or health status is unusual.
Before saving the answer, check the units, decimal points and assumptions shown by the tool. If you compare results later, use the same method so the trend is meaningful. The GOLO Diet Plan covers the same topic from another angle.
Interpret the number in context
Use BMR as the starting component of a broader energy estimate. Activity, digestion, training, sleep, illness and spontaneous movement affect total daily expenditure and make real-world needs change from day to day.
The result should not be treated as a minimum eating prescription. Pregnancy, adolescence, eating-disorder history, medical conditions and substantial weight change require personalised professional guidance.
A practical next step
If using the number for planning, compare several weeks of intake and weight trend, then make small adjustments rather than reacting to one day’s result.
- Save the inputs with the date instead of recording only the final number.
- Look for a repeatable trend and avoid reacting to one unusually high or low result.
- Use qualified medical or coaching support when the decision affects health, treatment or safety.
Common questions
Is the result exact? No. It is the output of the displayed formula and the information entered. Measurement error and individual variation still apply.
How often should it be recalculated? Recalculate when the underlying inputs meaningfully change. Repeating it several times a day usually adds noise rather than useful information.
Can it replace professional advice? No. It is an educational planning aid and cannot assess symptoms, diagnose a condition or account for a complete personal history.