You've heard of this cardinal rule: If you want to burn fat, you've got to create a calorie deficit in your body. This means you need to use up more calories than what you ingest. Of course, we know that exercise causes the body to use up more calories. When practiced with a healthy diet, the body burns more fat and eventually loses the excess weight.

But how many calories does your body really need to be able to perform its day-to-day function and keep you energized all throughout the day? If weight loss is your primary concern, how many calories less do you need to eat everyday to burn the fat? Calorie counting is hard enough as it is, but if you don't know exactly how many calories you need to lose then it's like going to battle unarmed.

The calorie calculator, however, is a very useful tool that provides the solution to this dilemma. By taking into consideration such factors as your height, weight, gender and activity level, the calorie calculator estimates how many calories your body needs everyday to maintain your current weight level. If you want to lose weight, you have to eat 500 to 1000 calories less than what you actually take each day. If you want to gain weight, then do the opposite, eat 500 to 1000 calories more than what you actually burn everyday.

Men and women need to take in somewhere between 1200 to 1800 calories everyday. Now take note that these are merely general figures and are not all are the same for everyone. Men naturally burn more calories because of their muscle mass, and while the figures spouted by a calorie calculator may not be set in stone, they serve as good starting points for gaining, losing or maintaining weight.

Using the calorie calculator then becomes important because you are able to monitor how many calories you're losing on a certain day, especially if you're working to lose weight. Gradual calorie loss- meaning no more than a thousand calories per day- is important if you wish to avoid the devastating effects of yoyo dieting and wrecking your metabolism. If your body has too little calories, your muscle mass gets broken down to supply the energy your body needs. This process, known as catabolism, leads to a slowing down of your metabolic rate. When the latter occurs, you become sluggish, irritable and experience nutritional deficiencies. This also sets the stage for you to regain more fat the moment you resume your normal eating habits.

At this point, the only way to address the issue is to trick the body into boosting metabolism through a variety of ways, including zigzagging or cycling calories, manipulating macro-nutrient ratios and eating occasionally high-calorie meals. Increasing cardiovascular exercise will also boost one's metabolism and put you back on track in your weight-loss, weight-gain or weight-maintenance program.

Needless to say, you need the help of a calorie calculator for this. From those interactive online varieties to pocket varieties, calorie calculators are very useful tools to keep you healthy and fit by counting your calories for you.