If you have hit a plateau and you are also wondering how much to take in, consider doing a test for RMR/BMR. There is this thing, I think it is called MedGem, where you breathe into a tube for 10 minutes, while sitting extremely still. The number you get back is a good indicator of BMR/RMR. I think there are differences between the two but I forget what exactly it is.
anyways, I found that the BMR calculators underestimated my caloric needs. I was several hundred calories over what they all estimate. So I guess I have a fast metabolism.