At your current low weight, 1800 might be a bit high. The less you weigh, and less you have to lose, the less calories you can eat and lose. It might be better to concentrate on losing fat and firming up. Maybe start at 1400 or 1500 calories a day and start exercising (if you don't already). Losing weight just makes you a smaller version of what you are now. Losing fat with exercise helps you firm up and change your body composition. Get plenty of lean protein and high fiber because they help you lose weight and fat the best. Keep processed foods to a minimum. Play around with the calories till you find what works for you. Good luck!