Weigh the raw or cooked weight of the food ingredients before cooking, convert it by the ratio of raw to cooked, and combine it with the calorie content of each food in the food composition table.

The simple algorithm can be estimated by exchanging portions of food, with one portion being about 90 kcal or 90 calories. One serving of a staple food is about half a tael, such as half a fist-sized bun or rice or 1 slice of sliced bread.

A portion of fruit is about 200 grams, such as a medium-sized peach, and a portion of meat is about 1 tael, such as the size of the palm of your hand. A serving of milk is about 150 milliliters, a serving of eggs is 1 egg, a serving of vegetables is about 1 pound, and a serving of oil is about 10 grams. Add up all the servings and multiply by 90 calories to get your total energy intake for the day.

Using the Harris Benedict Formula, multiply your BMR by the activity factor (below):

Barely Moving Calorie-Calculation = BMR x 1.2.

Slightly Exercising (1-3 times per week) Total Required = BMR x 1.375.

Moderate Exercise (3-5 times per week) Total Needs = BMR x 1.55.

Active Exercise (6-7 times per week) Total Needs = BMR x 1.725.

Professional Exercise (2x the amount of exercise) Total Needs = BMR x 1.9.

Say you calculate a BMR result of 1,745, with essentially no exercise. Then you need 1745 x 1.2 = 2094 calories to maintain your current weight.