It is possible to get a flat stomach in as little as 30 days, but just wanting it is not going to make it happen--you are going to have to put in the work. Some basic abdominal exercises that will have your stomach looking flat in no time and will work to not only reduce belly fat, but strengthen your core. Work your abs every day, doing each exercise until your muscles feel exhausted.
Do at least 50 crunch sit-ups. These are small, quick sit-ups. When you do a crunch, you need to be in the same position as you would for a sit-up. Lift your shoulders towards your knees using only your stomach muscles but do not lift your entire upper body. Exhale as you lift up and inhale as you lower back down.
Do a set of the plank abdominal exercises. This is a core exercise: Lie face down on the floor with your hands palms-down under your shoulders. While keeping your spine and head straight, lift your weight onto your toes. Stay in this position for as long as possible using only your abdominal muscles.
Complete a set of jack-knife sit-ups. These start like a typical sit-up, except you point your legs towards the ceiling. Lift your shoulders up off of the floor using only your abdominal muscles. When this exercise gets too easy, lift your hips off of the floor at the same time you lift your shoulders.
Add the balance ball to any of the above exercises, except the plank, every other day. When doing crunches on the balance ball you will keep your feet on the floor with your lower back lying on the ball; hold your head behind your hands and lift your upper body toward the ceiling with only your ab muscles. To do the jack-knife sit up on the ball, you will need lie on the ball, keeping your lower back connected to it. Keep one foot on the floor and raise the other as high as you can. Lift your upper body to the ceiling while maintaining balance. Do ten reps and then switch feet.
Implement an overall program to lower your body fat, because you can't spot-reduce excess fat from around your stomach. You must burn more calories than you ingest to lose weight. Performing aerobic exercises such as jogging, swimming, jumping rope or using an aerobic machine -- such as an elliptical -- are among the best ways to increase your calorie burn. Eat a sensible diet, including fruits, vegetables, whole-grain breads and lean protein, while avoiding sugary and high-fat foods.