Daily Caloric Intake - Why are there so many differing figures?

I have been visiting various websites for information on weight loss and daily calorie intake, and every time I enter my stats (weight, height, gender, age) at a different site, I get different figures each time! And I'm not talking about a few calories here and there, I'm talking about 500+ calories! Some websites, I'm told my daily maintenance level is 2, 050 calories, where others tell me it's 1, 500… This is a very big difference, especially considering that in order to lose 1 pound a week, you'll ideally cut out 500 calories per day… This makes things harder to actually figure out how many calories you need to eat and burn when the recommended base calories are so different with each website! Why are all these websites' figures so different? And which website has the MOST accurate daily caloric intake calculator? Or, is there some formula that's the most accurate that I can use to just figure it out myself? I have been using the Lose It app on my iPhone to check my calories, but according to the app, I'm allowed to have more than 1, 600 calories a day and still lose 1 pound a week, which is crazy, because at 5' 0," I highly doubt I need 2, 100 just to stay alive… I'm very confused. Please clarify for me.

Make it easy on yourself.eat the fewest calories you can while still satiating hunger.

Maybe this will help