I hate BMR formulas, especially ones that are based only on weight. Telling a person how much they can/should eat based on a simple number is tantamount to trying to describe an entire forest based on a drawing of a leaf.
The honest to God best way to figure out how much you should eat sucks. It's going to take effort and time, but you're just going to have to experiment. You should be eating enough that you have enough energy to make it throughout the day without a nap really, and still get your workout in. If you don't, you may need to pure more carbs (yes, I said MORE carbs, carbs are not the enemy, despite what trendy diet fans will tell you) in your diet or just adjust your diet altogether.
It took me about a month of playing around with my diet to figure out how much to eat to lose weight without losing muscle; now that i'm going into a building phase, especailly since my muscle mass is different than how it was before, I'm having to go through that process again, but with a better baseline to start from.
And if I may be blunt, focusing on calories and JUST weight are going to lead you down a number crunching nightmare of a road to nowhere. Focus on eating smart, focus on getting to the gym and just don't gorge yourself. If you're eating in an excess but working out, your body will build muscle which burns fat. If you're eating in a deficit, your body will burn away fat (and muscle too if it's too much of a deficit!). The key is really not to eat too many empty calories.
I assume that you're working out to a) be healthier and b) look better and, along those lines, the absolute BEST thing you can do is invest in a body fat analyzer, whether it's a scale or calipers and track that number. Make sure it keeps going down, if it ends up trending upwards re-analyze your eating and exercise habits.