Calorie Calculator: Daily Energy Needs
By Hesaplayıcı
The calorie calculator estimates the energy your body uses in a day. Enter your sex, age, weight, height and activity level. It first finds your basal metabolic rate with the Mifflin–St Jeor equation, then multiplies it by an activity factor. The result is in kcal per day and is not medical advice.
Worked example: A moderately active woman, 31 years, 65 kg, 168 cm
Daily calorie need
2,145 kcal/day
- Basal metabolic rate (BMR)
- 1,384 kcal/day
Step by step
Basal metabolic rate (BMR)
BMR = 10 × weight + 6.25 × height − 5 × age − 161
BMR = 10 × 65 + 6.25 × 168 − 5 × 31 − 161 = 1,384 kcal
Daily calorie need
daily energy need = BMR × activity factor
daily energy need = 1,384 × 1.55 = 2,145 kcal
How to use
- Choose your Sex: Female or Male.
- Enter your Age in years, your Weight in kilograms and your Height in centimetres.
- Choose the Activity level closest to your weekly exercise.
- Press Calculate.
Formula
BMR (men) = 10 × weight + 6.25 × height − 5 × age + 5BMR (women) = 10 × weight + 6.25 × height − 5 × age − 161Daily calorie need = BMR × activity factor
BMR is the basal metabolic rate in kcal per day. Weight is in kilograms, height in centimetres and age in years. The activity factors are the American Council on Exercise table: sedentary 1.2, lightly active 1.375, moderately active 1.55, very active 1.725, extremely active 1.9. Both results are rounded to whole kcal.
Worked example
The worked example on this page shows a woman of 31 years, 65 kg and 168 cm who exercises 3–5 days a week. The steps give the basal metabolic rate and the daily calorie need with the moderate activity factor.
Limits
The equation comes from healthy adults and gives an estimate; a measured value can differ from person to person. Pregnancy, breastfeeding, illness, medicines and a high muscle share are not taken into account. The calorie gap needed to lose or gain weight is not calculated. The result is not medical advice; ask your doctor or a dietitian about a diet plan.
Frequently Asked Questions
What is the basal metabolic rate?
It is the energy your body uses in a day at rest, for its basic functions only. The calculator estimates it with the Mifflin–St Jeor equation.
Which activity level should I choose?
Sedentary if you have a desk job and no exercise; lightly active for exercise 1–3 days a week, moderately active for 3–5 days, very active for 6–7 days. Extremely active fits training twice a day or hard physical work.
Why the Mifflin–St Jeor equation?
It was developed in 1990 from the resting energy expenditure measured in 498 healthy adults. The same study found that the older Harris–Benedict equations overestimated the measured value by about 5%.
Does the result tell me how much to eat to lose weight?
No. The calculator gives the estimated energy to keep your weight. Ask your doctor or a dietitian about losing or gaining weight.
Calculation rules
- The BMR uses the Mifflin–St Jeor equation (Mifflin et al., Am J Clin Nutr 1990): for men 10 × weight + 6.25 × height − 5 × age + 5, for women the same sum − 161.
- The daily need is BMR × activity factor. The factors (1.2, 1.375, 1.55, 1.725, 1.9) are the American Council on Exercise (ACE) table.
- The BMR and the daily need are rounded to whole kcal; the daily need uses the rounded BMR.
- The equation comes from healthy adults; pregnancy, breastfeeding, illness and athletic body composition are not taken into account. The result is an estimate, not medical advice.