BMR Calculator
Estimate resting daily energy with the Mifflin–St Jeor equation. Compare metric and imperial inputs.
Your estimate
Enter your values and calculate. Results will appear here.
This is a resting-energy estimate, commonly searched for as BMR. Mifflin–St Jeor predicts resting energy expenditure, which is not identical to a tightly controlled laboratory BMR measurement. It excludes the activity multiplier used in our daily calorie tool.
How to use this calculator
Choose units, enter current height and weight, then age and the coefficient required by the original equation. Calculate before changing one input to compare scenarios. This tool accepts ages 20–80; that interface boundary does not establish that the equation is equally accurate throughout that interval.
Formula and methodology
Resting energy = 10 × kg + 6.25 × cm − 5 × age + sex coefficient (male +5; female −161), kcal/day.
Worked example
For a 30-year-old using the male coefficient, 70 kg and 175 cm gives 700 + 1,093.75 − 150 + 5 = 1,648.75, displayed as 1,649 kcal/day. Choosing the female coefficient with the same measurements gives 1,483 kcal/day after rounding.
What the result means
This is a resting-energy estimate, commonly searched for as BMR. Mifflin–St Jeor predicts resting energy expenditure, which is not identical to a tightly controlled laboratory BMR measurement. It excludes the activity multiplier used in our daily calorie tool.
Limitations
Do not use resting energy as a daily food allowance. Body composition, illness, medications and individual metabolism can make measured expenditure differ from the equation. The two sex coefficients reflect the source model and cannot represent every physiology.
Common mistakes
Entering pounds as kilograms changes the estimate substantially. Another common error is adding exercise calories to BMR while overlooking the rest of daily activity.
Frequently asked questions
Is BMR the same as maintenance calories?
No. Resting energy describes a baseline. TDEE adds an approximate allowance for daily activity and other expenditure.
Why is there no activity field?
Activity belongs in the TDEE estimate, not in this resting-energy equation.