Ok, so my goal is to lose about 2lbs or more (won't turn it down!) per week.
Fitday says I can do this by eating 2,600 calories a day. Ugh! I don't think this is true, as I dont recall ever losing weight while eating that many calories. I even updated my profile to show a (sadly) sedentary lifestyle.
What is up with fitday? Which free online program has a better estimation of calories needed per day to effect a significant weight loss? So far, the daily plate has been pretty good.
I use fitday, and yes the ads are god-awful. I love that a website dedicated to fitness and healthy eating has ads promoting weight loss surgery. Very predatory! I believe they grossly overestimate how many calories I need, as well, but I still use the site to keep track of my meals and nutrition %. I ignore their recommendations for caloric intake and just eat 1500-1600.
ANY calculator is just an estimate. Almost all calorie calculators give me numbers that I have tried to maintain on, and my body does not match whatever "average" they used to calculate on.
They can provide a good baseline, but your body will tell you how many calories it needs. Gaining weight? You're eating more than you need. Maintaining? That's your maintenance level. Losing? You're eating less than you need.
I don't know how old you are or how tall you are, but at 300+ lbs, pretty much any calculator is going to put your base burn rate fairly high. Plenty of people have chosen to go much lower, even at a high starting weight, but that doesn't change the way all these calculators work.
As mandalinn says, they are just a starting point anyway. Pick a number, try it for 3 weeks and see if you are getting the results you want and feel good while eating that amount. Then adjust up or down as needed.
fwiw, I track my calorie burn with a Gowear Fit and it's lower than any of the calculators I've used.
That's so funny; I have the opposite issue. I'm 5'3, 159 lbs. I want to get back to 120. Calorie counters tell me to eat roughly 1200 calories to lose 1 lb a week, but I consistently lose 2 a week (or 0 one week, 4 the next!) on a 1400-1600 calorie diet...and some days I'm as high as 1800. Go figure.
Before computers were in the average home, and even before calculators were in the average home, weight loss calculation "math" have been available.
Algebra was a snap for me in junior high and high school, because I already had learned the basics (without realizing it) by using "weight loss math."
So - I found that the "math" worked pretty well in my teens (I lost what the calculators estimated I would on the calorie level, I'd chosen). By my mid twenties, I was already losing less than the calculator estimates. And with every diet, and every year the calculators overestimated more and more how much I "should" lose on any calorie level.
It's why I firmly believe that metabolism does (or at least can) drop (and disproportionately so) as a result of yoyo and crash dieting.
Ultimately, your metabolism is what it is. The calculators are like going to a fortune teller, "for entertainment purposes only."