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Miraç Özdemir
Calories & Nutrition

BMR and Daily Calorie Needs Calculator

Calculate your basal metabolic rate (BMR) with the Mifflin-St Jeor equation and your daily calorie needs from your activity level, plus daily calories for a weight loss or gain goal.

Version 3

Things to keep in mind:

  • The equations are based on averages of healthy adults; an individual metabolism can differ by ±10 % or more.
  • They are not suitable for children and adolescents, pregnant or breastfeeding women, people with chronic illness or very muscular athletes; their energy needs are assessed differently.
  • Goal calories can fall below BMR; very low calorie diets should only be followed under medical supervision.
  • The activity level is self-reported and often overestimated; evaluate the results together with your actual weight trend.
  • The result is an estimate, not a medical diagnosis or treatment advice; consult your physician or dietitian for decisions about your health.

Calculator

Personal details

Sex

Your age in whole years (18–100).

Enter your body weight in kilograms (e.g. 72.5).

Enter your height in centimetres (e.g. 175 or 172.5).

Activity and goal

Basal metabolic rate is multiplied by this factor to estimate daily energy expenditure.

A fixed calorie difference is added to or subtracted from daily energy expenditure.

After the first calculation, the result updates automatically when you change a value.

Result

Enter the values and press Calculate to see the result here.

About this tool

Basal metabolic rate (BMR) is the energy your body uses at rest for its basic functions. The calculator uses the Mifflin-St Jeor (1990) equation, the most widely recommended predictive equation today, and shows the Harris-Benedict equation as revised by Roza and Shizgal (1984) for comparison.

Formulas (weight kg, height cm, age years)

  • Mifflin-St Jeor: BMR = 10·weight + 6.25·height − 5·age + 5 (men) / − 161 (women)
  • Harris-Benedict (revised): men 88.362 + 13.397·weight + 4.799·height − 5.677·age; women 447.593 + 9.247·weight + 3.098·height − 4.330·age
  • Daily energy expenditure = BMR × activity factor (1.2 / 1.375 / 1.55 / 1.725 / 1.9)
  • Goal calories = daily expenditure + goal adjustment (0, ±250 or ±500 kcal)

A deficit of about 500 kcal a day corresponding to roughly 0.5 kg a week is a common rule of thumb; actual weight change slows over time as metabolism adapts.

Example: for a 30-year-old man weighing 80 kg at 180 cm, BMR = 800 + 1125 − 150 + 5 = 1780 kcal. At a moderate activity level (×1.55) daily expenditure is 2759 kcal, which is also the target for maintaining weight. Harris-Benedict gives 1854 kcal for the same person.

How to use

  1. Select your sex and enter your age, weight and height.
  2. Choose your physical activity level.
  3. Choose your goal.
  4. Press Calculate.

Notes

All results are in kcal, rounded to whole numbers (HALF_UP). Daily expenditure and goal calories are computed from the unrounded BMR. The activity factors are the commonly used standard values; the goal adjustments are fixed and the weekly weight changes are approximate.

Sources

References

  1. [1]
    A new predictive equation for resting energy expenditure in healthy individualsMifflin MD et al., Am J Clin Nutr, 1990
  2. [2]
    The Harris Benedict equation reevaluated: resting energy requirements and the body cell massRoza AM, Shizgal HM, Am J Clin Nutr, 1984

Frequently asked questions

4 questions

  1. It is the daily energy your body uses at complete rest to maintain basic functions such as breathing, circulation and body temperature.

Next step

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