The total number of calories someone needs each day depends on multiple factors. This number depends on age, sex, height, weight, metabolic rate, and physical activity level. Other factors depend on specific goals including weight loss, weight gain or maintenance. In order to achieve any of these goals we have to consume a certain amount of calories.
What is a calorie?
A calorie is basically a unit that measures energy. They are usually used to measure the energy content in foods and beverages. Therefore in order to lose weight you will need to consume fewer calories than your body burns each day and if you want to gain weight you will need to consume more calories than your body burns daily.
How many calories do we burn every day?
Basal metabolic rate (BMR) also known as resting metabolic rate (RMR) or resting energy expenditure (REE) is the rate your body burns energy when it is at complete rest. A common equation used to find out your BMR is called the Mifflin St. Jeor Formula. Note that this formula provides a rough estimate and is not always accurate.
Mifflin St. Jeor Formula:
Men: (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5
Women: (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161
I have provided a BMR calculator below.
Certain types of activities burn more calories than others. Harvard Health created a graph that suggests how many calories are burned during 30 minutes of various activities. This graph includes calories burned based on 3 different weights, a 125 pound person, a 155 pound person and a 185 pound person. Click here to view the graph.
Calories Related to Goals
Total caloric intake is the amount of calories you should be consuming everyday based on your goals. Provided below is a calculator suggesting approximately how many calories you should be consuming every day.
Health.gov also provides a chart with all ages for both male and female that roughly suggests how many calories one should consume. Click here to view the chart.
Personally when my goal is to gain weight I like to increase my calories by 500 a day and when I want to lose weight I like to decrease my calories by 500 a day. This leads to about 1 pound every week. For example I exercise for about 1 hour each day and to maintain my weight I consume about 2,500 calories. When I want to gain weight I increase it to 3,000 calories and when I want to lose weight I decrease it to 2,000 calories.