| dude, those BMR calculators are absolutely worthless. there are far too many variables to consider such as weight, bodyfat, lifestyle, activity level, food choices, genetics, etc. the best way to find YOUR maintenance level is through trial and error.
chris aceto describes an effective approach: weigh yourself upon awakening when you start and again after your trial. record the numbers of cals taken in each day for X amount of days (obviously, the more days you go lessens the margin of error) and weigh yourself again after the trial. divide the total cals consumed over that time period by the number of days tested and viola!
for example, lets say you start at 190 lbs. your cal intake over the next 3 days are 2600, 2450, 2450. after 3 days, you still weigh 190 lbs. your total cal intake over that time is 7500/3 days = 2500 cal maintenance. this only works if your weight remains constant. personally, i dont worry about this stuff cause your metabolic rate changes daily. | 
