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BMR calculator

Basal Metabolic Rate: the calories your body burns at complete rest. Your body's minimum running cost.

Units

Sex

The equation uses sex-specific coefficients.

years
cm
kg

Your BMR

1730kcal

per day

Mifflin-St Jeor equation

Daily burn by activity level

  • Sedentary: little or no exercise2076kcal
  • Exercise 1-3 times a week2379kcal
  • Exercise 4-5 times a week2534kcal
  • Daily exercise, or intense exercise 3-4 times a week2682kcal
  • Intense exercise 6-7 times a week2984kcal
  • Very intense exercise daily, or a physical job3287kcal

Exercise counts as 15-30 minutes at elevated heart rate; intense exercise as 45-120 minutes.

1. What BMR tells you

BMR is the energy your body spends doing nothing: breathing, circulation, cell repair, keeping your brain running. For most people it is the largest share of daily burn, bigger than training and daily movement combined.

Every calorie target starts here. Eating below your total burn moves weight down, eating above it moves weight up, and BMR is the floor that total is built on.

2. The equation

This calculator runs Mifflin-St Jeor, published in 1990 and recommended by the Academy of Nutrition and Dietetics over the older Harris-Benedict formulas.

Men
10 × weight + 6.25 × height - 5 × age + 5
Women
10 × weight + 6.25 × height - 5 × age - 161

Weight in kilograms, height in centimetres, age in years. The app runs the same equation from your profile and rounds to a whole number of kcal.

3. From BMR to daily burn

Total daily burn is BMR times an activity factor. The table under the calculator runs all six standard multipliers at once, so you read the whole ladder instead of picking one band blind:

Activity levelMultiplier
Sedentary: little or no exercise1.2
Exercise 1-3 times a week1.375
Exercise 4-5 times a week1.465
Daily exercise, or intense exercise 3-4 times a week1.55
Intense exercise 6-7 times a week1.725
Very intense exercise daily, or a physical job1.9

The factor is the roughest part of the estimate. One band too high on a 1700 kcal BMR adds several hundred calories, which is why the app saves the raw BMR and lets your logged sessions carry the activity story.

4. How close it gets

Validation studies put Mifflin-St Jeor within 10 percent of measured resting burn for most adults. Muscle is the main reason it drifts: the equation only sees total weight, so a muscular build burns more at rest than the estimate shows.

Treat the number as a starting point and let the scale confirm it. Two weeks of stable weight at a known intake beats any equation.

5. The same math in the app

BDYCTRL calculates BMR inside the measurement log, prefilled from your profile, and saves it with the rest of that day's measurements. Get the app.