You can do a calculation of your Basal Metabolic Rate, which will give you your resting/baseline calorie intake, and then add in the activity you add to that.
I don't think "weight x 10=calories" or "weight x 3=calories" are correct or incorrect... if you eat about 2000 calories, you'll probably lose some weight consistently, and if you go under that, you are on a somewhat aggressive weight loss setting. If you are particularly active (in terms of recreation and labor) 2000 might not be enough to maintain weight. It might not be bad to try a halfway point... but checking to see how much you are actually eating, and taking a real inventory would be a good idea over a few weeks.
Be honest, and behave normally over that time, then take a look at real steps you can take. The answers are not always simple, and are rarely easy...