Here's a quick and easy way to get started when you want to CUT instead of BULK. Mind you, this is merely a starting point template. You will need to make adjustments along the way. Also, there is no such thing as a one-size-fits-all formula. Keep that in mind.
Before you can CUT (or bulk, for that matter), you need to know what your maintenance calories are daily. To find out, you need to weigh yourself DAILY FOR 2 WEEKS, while also keeping track of what you eat. After two weeks, tally your average daily weight. You also need to tally your average daily caloric consumption.
Once you know these figures, you can adjust your caloric needs according to your CUT (or bulk).
If you don't want to do all that work, then you can start with the formulas in the picture.
Keep in mind that you need to know how active you are to begin with. Since most are sedentary, besides working out 3-6 days a week, this number is 1.45. If you're very active AND you lift weights 3-6 days a week, then your number would be closer to 1.8.
NOTE: THIS IS NOT MEANT FOR THE BEGINNER.
Once you figure out your macros based on the formulas above, you need to track your daily weight, which is in the morning before you eat, but after you go to the bathroom. Also, YOU MUST track your daily caloric intake.
Do this for at least a week or two. This is going to establish your daily maintenance. Following this method will quickly show you if your weight is going up, down or staying the same.
It's a GOOD THING if it stays the same. This means that your maintenance levels have been established. From this point, you need to reduce your daily caloric intake to CUT. If you were bulking, then obviously, you'd have to increase your daily caloric intake.
For actual methods of calculating YOUR CUTTING calories, I highly recommend that you hire a professional, licensed Nutritionist--or do your own research.