BMR Calculator.

How the BMR Calculator works.

BMR Calculator example using the starting values.

This BMR Calculator example uses the starting inputs: Weight (kg): 70, Height (cm): 175, Age: 30, Sex: male.

Result: 1649 kcal/day

Estimated resting energy, not a diagnosis.

BMR: 1649 kcal/day

What the result means

Estimate resting energy needs with Mifflin–St Jeor. The BMR Calculator result describes only the measurements and method shown; it is not a diagnosis or an individualized target.

Enter a consistent scenario

Use BMR Calculator with values from one clearly defined scenario. The visible inputs are weight (kg), height (cm), age, sex. Mifflin–St Jeor estimates resting energy from age, sex, height, and weight. It cannot measure an individual metabolism, illness, medication effects, pregnancy needs, body composition, or a safe calorie target. Check the unit, period, and meaning of each value before calculating; combining records from different dates can produce a precise-looking but unhelpful answer.

Follow the method

This page applies Mifflin–St Jeor equation. Mifflin–St Jeor estimates resting energy from age, sex, height, and weight. It cannot measure an individual metabolism, illness, medication effects, pregnancy needs, body composition, or a safe calorie target. First identify what each entered value represents, convert a percentage to the form required by the displayed formula, and retain intermediate precision. Then make a rough mental check of direction and size. Estimate resting energy needs with Mifflin–St Jeor. The worked result is transparent arithmetic rather than an unshown lookup.

Use the result carefully

Read the output as an answer to the narrow question described by the fields, not as a prediction of every real-world outcome. Mifflin–St Jeor estimates resting energy from age, sex, height, and weight. It cannot measure an individual metabolism, illness, medication effects, pregnancy needs, body composition, or a safe calorie target. For BMR Calculator, compare results only when the measurement basis, time period, currency denomination, or grading convention is the same. This is general information, not a diagnosis, treatment target, or substitute for individual clinical care. Discuss symptoms, pregnancy dating, nutrition, exercise, or a concerning result with a qualified clinician.

Assumptions and boundaries

Before relying on BMR Calculator, identify what its formula—Mifflin–St Jeor equation—holds constant and what it does not observe. Mifflin–St Jeor estimates resting energy from age, sex, height, and weight. It cannot measure an individual metabolism, illness, medication effects, pregnancy needs, body composition, or a safe calorie target. Its entries (weight (kg), height (cm), age, sex) define the full scope of this particular result. Do not turn a rounded display into more certainty than the entered data supports; use the official record or provider documentation where it controls.

Common mistakes and next steps

For BMR Calculator, begin a review by comparing the displayed weight (kg), height (cm), age, sex against the source record. Mifflin–St Jeor estimates resting energy from age, sex, height, and weight. It cannot measure an individual metabolism, illness, medication effects, pregnancy needs, body composition, or a safe calorie target. Typical mistakes are entering a percent as a decimal or vice versa, using an amount from the wrong time period, rounding before the final step, and treating an estimate as an official determination. Record the inputs and result if you need to compare scenarios later.

What the BMR Calculator does not include.

This BMR Calculator result is an estimate, not a diagnosis or treatment plan. Seek urgent care for concerning symptoms and discuss pregnancy, diet, sleep, or activity decisions with a qualified clinician.

Official context and guidance.

• CDC — About Adult BMI (opens in a new tab)