To use the calculator simply enter your details including the desired amount of weight you wish to lose and the time-frame (in days) in which you would like to lose that excess weight - (You can also use the calculator to plan weight gain.) For your convenience the calculator converts pounds to kilos, inches to centimeters, and vice versa. Or you can convert between Pounds Kilograms and Stones.
Are you ready to give the calorie calculator a try? You'll need to provide some vital information about your age, gender, height, and your current weight to get the right calorie number. The calculator requires this data because these are factors that influence your metabolic rate—or the number of calories that your body needs to function. In general, men need more calories than women. Larger bodies need more calories than smaller bodies, and younger adults require more calories than older adults. 
Athletes at their prime must consume many more calories than the average person to be at peak performance, but as they age and become less active may find that their old eating habits are hard to break. Former athletes who have gained weight and want to become lean and muscular as they age may turn to weight loss programs for help getting on track.

If you’ve been eating fast food for years, get real about your approach: You’re probably not going to stick to an organic, gluten-free, paleo overhaul for very long. “You want to change as little as possible to create calorie deficit,” says Dr. Seltzer, who insists the best way to support sustainable weight loss is to incorporate small changes into existing habits. So instead of giving up your daily BLT bagels in favor of an egg-white wrap, try ordering your sandwich on a lighter English muffin. Or say you eat a snack bar every afternoon: Swap your 300-calorie bar for a 150-calorie alternative. “Your brain will feel the same way about it, so you won’t feel deprived,” he says.