Calorie requirement calculatorUpdated on by Stefan Banse
Would you like to know how high your daily calorie requirement is? With the calorie requirement calculator, you can calculate your individual calorie requirement. The calorie requirement calculator determines your daily basal metabolic rate and active metabolic rate.
Example for calculating calorie consumption
The calorie requirement is equal to basal metabolic rate plus active metabolic rate
To calculate the calorie requirement, the total metabolic rate is calculated using the sum of the basal metabolic rate and the active metabolic rate. We explain what this is and how it is calculated below.
Basal metabolic rate (BMR)
The basal metabolic rate is the daily calorie consumption without any exercise. It is calculated here according to the Harris-Benedict equation, which was developed in 1918 and is still considered to be a good guideline for calorie consumption today. The equation takes into account the fact that body weight, height, age and gender influence the basal metabolic rate.
Harris-Benedict equation for calculating the basal metabolic rate
|The following applies for women:|
|Metric||655.1 + (9.56 × weight in kg) + (1.85 × height in cm) − (4.7 × age in years)|
|Imperial||655.1 + (4.34 × weight in pounds) + (4.7 × height in inches) − (4.7 × age in years)|
|The following applies for men:|
|Metric||66.5 + (13.75 × weight in kg) + (5.0 × height in cm) − (6.76 × age in years)|
|Imperial||66.5 + (6.24 × weight in pounds) + (12.7 × height in inches) − (6.76 × age in years)|
The difference of the first summand is striking, namely 655 for women and 66.5 for men. This can be explained by the fact that the basal metabolic rate in men is more strongly determined by body stature and the associated muscle mass. Men therefore have a higher calorie requirement than women with regard to the basal metabolic rate according to the equation.
Correction of basal metabolic rate with high BMI
If you have a BMI above 30 kg/m², i.e., you are severely overweight, a corrected body weight (Broca Index adjustment) is automatically calculated in the calorie requirement calculation and included in the Harris-Benedict equation. This takes into account the fact that the basal metabolic rate per kilogram of body weight decreases as the body fat percentage increases. Click here for the BMI calculator.
Active metabolic rate
In addition to the basal metabolic rate, the active metabolic rate is also used to calculate the calorie requirement. The active metabolic rate is the amount of energy that is consumed in addition to the basal metabolic rate through work and leisure activities. A reliable calculation of the total calorie consumption is made using the PAL factors ("physical activity level"). For this purpose, five typical lifestyles were defined for adults based on their level of activity. Each of these lifestyles has a PAL factor that is derived from all the usual activities throughout the day. This is multiplied by the basal metabolic rate to calculate the total calorie consumption. The smallest PAL factor indicates the lifestyle with the lowest level of activity. The highest PAL factor of 2.0 to 2.4 is given to people with a high level of physical activity. On average, they consume more than twice their basal metabolic rate in calories.
The PAL factors used to calculate the active metabolic rate in detail
- Sitting or lying only (PAL 1.2)
People with an exclusively sedentary or recumbent lifestyle (e.g., old, infirm people)
- Sitting, hardly active (PAL 1.4-1.5)
People with an almost exclusively sedentary way of working and few leisure activities (e.g., people who work a great deal at a desk)
- Sitting, walking and standing (PAL 1.6-1.7)
People with predominantly sedentary and occasionally standing or walking activities and no or only slightly strenuous leisure activities (e.g., pupils, students, drivers, laboratory assistants)
- Predominantly standing/walking (PAL 1.8-1.9)
People with predominantly walking or standing jobs (e.g., housewives, waiters, craftsmen, shop assistants)
- Strenuous work/sport (PAL 2.0-2.4)
People with physically demanding jobs (e.g., farmers, miners, competitive athletes)
Increasing the PAL factor for intensive sport
If you participate in a significant amount of sport or strenuous leisure activities. (4 to 5 times per week for 30 to 60 minutes), the PAL value is increased by 0.3 units for the three activity levels "Sitting, hardly active", "Sitting, walking and standing" and "Predominantly standing/walking".
Total metabolic rate
The total metabolic rate is the sum of basal metabolic rate and active metabolic rate. It describes the amount of energy required per day to maintain weight. It corresponds to the total calculated calorie requirement.
Example: Calculation of the daily calorie consumption
Mr. Bold wants to calculate his daily calorie consumption and uses the calculator to determine the daily calorie requirement.
- Mr. Bold has a body weight of 120 kilograms.
- He has a height of 1.70 meters.
- He is 30 years old.
- Mr. Bold mainly performs office duties.
1. Calculation of the basal metabolic rate
Mr. Bold's basal metabolic rate is his daily calorie consumption without any exercise. It is calculated using the Harris-Benedict equation. This equation reads:
Harris-Benedict equation (metric)
66.5 + (13.75 × weight in kg) + (5.0 × height in cm) − (6.76 × age in years)
By inserting his inputs for weight, height and age into this equation, the following daily basal metabolic rate is determined to be:
Inserting Mr. Bold's values into the equation
66.5 + (13.75 × 120 kg) + (5.0 × 170 cm) − (6.76 × 30 years) ≈ 2 364 kcal/day
Preliminary basal metabolic rate for Mr. Bold
Mr. Bold's basal metabolic rate is 2 364 kcal per day, subject to adjustment for his heavy weight according to the Harris-Benedict equation.
1.1 Calculation of the BMI
Dependent on Mr. Bolds's body mass index (BMI) (evaluation of weight in comparison to height), the calculation of the basal metabolic rate using the Harris-Benedict equation may be subject to adjustment. This is because if the BMI is greater than 30, a reducing correction factor for weight is calculated before the equation is applied (Broca Index adjustment). This is because the basal metabolic rate per kilogram decreases with increasing body fat.
BMI of Mr. Bold
Mr. Bold's body mass index (BMI) is 120 / 1.70² ≈ 41.5
1.2 Consideration of the BMI for Mr. Bold's corrected basal metabolic rate
As Mr. Bold's BMI is above 30, a correction factor for his weight, the Broca Index adjustment, is first determined. The weight thus corrected is then used instead of his normal weight in the Harris-Benedict equation:
Broca Index adjustment for Mr. Bold
Mr. Bold's Broca Index adjustment is 0.75 × 170cm-100cm + 0.25 × 120kg = 82.5kg
Accordingly, the corrected weight for Mr. Bold is now to be inserted into the Harris-Benedict equation.
Inserting Mr. Bold's Broca-corrected weight into the equation
66.5 + (13.75 × 82.5 kg) + (5.0 × 170 cm) − (6.76 × 30 years) ≈ 1 849 kcal/day
Corrected basal metabolic rate for Mr. Bold
Ultimately, Mr. Bold's basal metabolic rate after the Broca Index adjustment of his weight according to the Harris-Benedict equation is 1 849 kcal per day.
2. Calculation of Mr. Bold's active metabolic rate
As described above, the active metabolic rate is the amount of energy consumed in addition to the basal metabolic rate from work and leisure activities. For this purpose, a certain PAL factor ("physical activity level") is assigned to the predominant activities of a person. This PAL factor then determines the calculation of the active metabolic rate.
Mr. Bold mainly performs office duties. According to this, he receives a PAL factor of 1.45, whereby the following applies: basal metabolic rate × PAL factor = total metabolic rate.
Active metabolic rate for Mr. Bold
Mr. Bold's daily active metabolic rate according to his PAL factor is 1 849 kcal × 0.45 = 832 kcal.
3. Calculation of his total metabolic rate
Mr. Bold's daily total metabolic rate in kcal corresponds to the sum of his basal and active metabolic rate.
Total metabolic rate for Mr. Bold
Mr. Bold's daily total metabolic rate amounts to 1 849 kcal + 832 kcal = 2 681 kcal.
4. Calculation kcal - kJoule
The equation for converting kcal to kJ is 1kcal = 4.18684 kJ
Mr Bold's daily total metabolic rate in kJoule
Mr Bold's total metabolic rate in kJ amounts to 2 681 kcal × 4.18684 = 11,225 kJ
With the Calorie-Joule Converter you can also conveniently convert between the two common units calories and joules with a slider.
As source for the information in the "Calorie requirement" category, we have used in particular:
Last update on November 26, 2020
The pages of the "Calorie requirement" category were last editorially reviewed by Stefan Banse on November 26, 2020. They all correspond to the current status.
Previous changes on June 25, 2020
- January 1, 2020: Publication of the calorie calculator.
- Editorial revision of all texts in this category