This calorie need calculator provides you your daily calorie need. Consume same amount of calorie daily to maintain your weight. For weight loss consume 450 to 500 calorie less than your daily need.
If you are not much active select 'sedentary' as your activity level. If you are somewhat active and do moderate exercise 2-3 times a week select moderately active. If you are very active, do heavy exercises habitually or actively participate in outdoor sports then select very active.
Check calorie chart for getting an idea about calorie values in different food items.