Getting a flat stomach depends on two main factors: where you are starting from and what your definition of a “flat stomach” is. It is realistic to say that you can achieve a flatter stomach in as little as **6-12 weeks** with a sound diet and exercise approach that places you in a slight and progressive caloric deficit for that time period.
To get a flatter stomach, you need to lose body fat, which can take **6-12 weeks** depending on how much fat you need to lose. You may start seeing signs of progress within a few weeks of consistent exercise, but it can take from a few months up to a year of work before you see the full results.
I hope this helps. Let me know if you have any other questions.