What is the best way...

To find out how much I need to consume in a day to be able to slim down a bit and tone up? I’m currently 133lbs @ 5’5 tall. I would like to lose a little more weight, but my main goal is to tone up. I do track my calories sometimes through My Fitness Pal, but not often. I would say I eat about 1200-1400 calories per day and usually burn between 400-600 calories during exercise. How do I know if my calorie intake is enough or too much? Again, not really concerned with losing weight so I’m not trying to be in a caloric deficit. Thanks!!