If you’re over 20 and basically have a sedentary job, then take your current weight (if you’re happy with your weight) or ideal weight (if you wish to lose weight) and multiply it by 10. This is a simplification, use a calculator if your weight is over 200 pounds. This number is pretty accurate give or take 100 calories.
how many calories do I need?
As an example, I’m 113 pounds. That means I can eat 1,130 calories a day without gaining weight, more if I’m active and exercise regularly.
If I was 20 pounds overweight, eating 1,130 calories instead of 1,330 calories will mean a deficit of 200 calories a day so that I lose a pound about every three weeks (3500 divided by 200), again, more if I exercise. That’s a safe, slow weight loss that will preserve muscle and only burn fat and won’t induce binge eating.