Calorie calculator. Gives a safe and healthy estimate of how many calories you really need. Stop starving yourselves out there! Low calorie diets can have many other long-term negative internal side effects to your organs and systems.
You always think you need to eat fewer calories, and exercise. In reality, you need to net at least 1200 calories to function. That means, if you're burning 300 calories, you need to ADD 300 calories to your diet in a healthy way to keep going.