hello fron Oklahoma

I started my diet back in February I have lost 22.9 pounds average and out about 2 pounds a week. I have a question about daily calorie intake when you put in your information it gives you the number of calories that you should be eating per day. But I have been stalling out a lot on that number I've been staying just a little under it. I am very active not so much exercise but my job is very physical. Wondering if I need to up my calories of that could maybe be the problem. Can anybody help me with us ? Does anybody know how to figure that exact amount of calories you should have a day for your body