Basal metabolic rate or BMR is the minimum calorific requirement needed to sustain life in a resting individual.
In order to calculate your daily calorie needs, you would have to determine the basal metabolic rate (BMR) using multiple factors such as your height, weight, age and gender, and then multiply the BMR by an activity factor. This will also determine your total daily energy expenditure (calories). The calculation method used is the Harris Benedict formula and the details are given below.
Method For Calculation
The Harris-Benedict Formula
The Harris Benedict equation is a calorie formula using the variables of height, weight, age, and gender to calculate basal metabolic rate (BMR). Since, as a philosophy, the leaner bodies need more calories than less leaner ones, this equation will be very accurate in most cases. However, discrepancies may occur for the very muscular (Harris-Benedict will under-estimate calorie needs) and the very fat (Harris-Benedict will over-estimate calorie needs).
Formula For BMR ( WOMAN)
BMR = 655 + (9.6 X weight in kilos) + (1.8 X height in cm) – (4.7 X age in years).
Formula for BMR (MAN)
BMR = 66 + (13.7 X weight in kilos) + (5 X height in cm) – (6.8 X age in years)
1. Example to calculate BMR (for women)
a. You are 32 years old woman.
b. You are 5 feet 4 inches tall (162.5 cm)
(Note-1 foot = 12 inches and 1 inch = 2.54 cm,
so 5 feet 4 inches = 5x 12 + 4=64 inches = 64x 2.54 = 162.5cms)
c. Your weight is 185 pounds (84 kilos)- (1 kilogram = 2.2 lbs.)
Therefore, your BMR is 655 + (806) + (291) – (150) = 1602 calories
2. Example to calculate BMR (for men)
a. You are 25 years old man.
b. You are 6 feet tall or 182.8cms
c. Your weight is 220 pounds or 100 kilos
Your BMR is 66 + (1370) + (914) – (170) = 2180 calories
To determine your total daily calorie needs, now multiply your BMR by the appropriate activity factor, as follows:
a) If you are Sedentary – little or no exercise
Calorie-Calculation = BMR X 1.2
b) If you are Lightly Active (light exercise/sports 1-3 days/week)
Calorie-Calculation = BMR X 1.375
c) If you are Moderately Active (moderate exercise/sports 3-5 days/week)
Calorie-Calculation = BMR X 1.55
d) If you are Very Active (hard exercise/sports 6-7 days/week)
Calorie-Calculation = BMR X 1.725
e) If you are Extra Active (very hard daily exercise/sports & physical job or 2X day training)
Calorie-Calculation = BMR X 1.9
Example to calculate Total daily calorie needs
If you are sedentary, multiply your BMR (1602) by 1.2 = 1922
Your total daily calorie requirement is therefore 1922 calories.
This is the total number of calories you need in order to MAINTAIN your current weight.
If you consume more than 1922 calories and fail to burn the difference, you shall hold the risk of gaining weight. To learn more about the different stages of being overweight, read on the forthcoming section on ‘Overweight Facts’