It’s not enough to just diet and exercise to lose weight; you also need to find out if you are consuming sufficient calories to lose weight. You have to either increase your exercise time or reduce your calories if you are consuming too many calories.

So the first thing you need to do is calculate calories needed to lose weight using the Harris-Benedict equation which is:

BMR + 655 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years).


Enter all the required details and the result you get is the total number of calories you need every day to exist or rather, your basal metabolic rate. As you’re not in bed all day long, you obviously burn more calories than this!

These activity factors help find out how many calories you burn through your daily activities:

  • Sedentary activity – minimal movement with lots of TV and reading, etc. – 1.4 Activity factor.
  • Light activity – office work and perhaps an hour of moderate exercise in the day – 1.5 Activity factor.
  • Moderate activity – light physical or manual labor in the day with an active lifestyle – Activity factor 1.6.
  • Very active – active military, people doing hard physical or manual labor job and full-time athletes – Activity factor 1.9.


Depending on the category you fit, multiply your Activity factor with your BMR. This gives the total number of calories you need to eat to maintain your weight. You thus need to eat less than this to lose weight.

There are various variables to find out how many calories needed to lose weight in a day affecting the number of calories in and out of your body. They are:

  • The exercise you do. You burn more calories after stopping exercise with resistance and interval training than traditional aerobic training.
  • Your diet. A high protein diet burns more calories as proteins need more effort to digest and metabolize.
  • The amount of weight to lose. It’s easier calculating this if you take your total body weight instead of your lean body mass which is total body weight minus body fat. If you need to lose 25 pounds to reach your goal, your calculated total caloric needs is too high as it was calculated based on the equal lean tissue and body fat caloric needs.


  • Your body metabolism. Any equation calculating your calorie needs give an estimate as people’s body metabolism rate differ. These equations just give you a starting point to use as reference to lose weight.

You generally need to subtract 500-1000 calories from your total calorie intake to lose 1-2 pounds a week as this leads to a 3500 calorie weekly deficit, or the number of calories needed to burn to lose a pound of fat. However reducing too many calories too soon can only lead to long-term weight loss failure.

If you do interval cardio sessions and weight training in the week and follow a carb-controlled with moderate protein diet, it’s enough if you subtract only 250 calories from your total calorie needs. You may reduce more if you plan to lose more than 25 pounds to reach your goal.


Now all your calculations done, you now have to find out how much of weight you’d lost at the end of a fortnight. If you are not losing as much weight as anticipated, it’s better you increase your workout first before reducing your calorie intake.

If you still need to reduce calories, just remove 250 calories from your present intake and try out the new calorie level the next week. With trial and error, you will learn how many calories needed to lose weight.