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.

I have an iphone 4s do i need a tablet?

Basically i have an iphone 4s and i use it for business but nearly everyonoe else has a tab. If i have a tab then it would certainly be the note 10.1.so what shall i do. No stupid answers please.

What's best way to recharge ipad & iphone faster?

I'm Mario, i have this problem on ipad & iphone. They don't recharge enough, so i was wandering, that is there way i can recharge them quicker also is there any cable that can recharge them quicker?

Wi-Fi won't turn on iPhone 4S? - 3

After my phone died one night my Wi-Fi setting to turn on turned light grey. It won't give me the option to even turn it on. I've tried resetting it (holding down the lock and home button until it restarts), I've tried just turning the phone off and back on, I've even tried connecting it to the computer but it won't back anything up therefore I really don't want to restore to factory settings.

Any ideas on how to make it able to turn on?

Added (1). Tried restoring network settings, still stayed light grey and won't give me the option to turn it on.

Added (2). Okay so I restored my phone to factory setting and it still won't give me the option to turn on Wi-Fi. I know that my house has Wi-Fi my laptop and xbox are currently on and connected to the Wi-Fi. I talked to apple support and they won't help me other then telling me to restore it.

Added (3). Interesting fact, iMessages are sending?

Added (4). Interesting fact, iMessages are sending?

How to sync my iPhone to my new laptop without deleting my music?

I just got a new laptop and want to download some new songs / rearrange my old songs onto different playlists. However, I can't do anything with my music because my iPhone isn't synced to my new laptop. If I sync it, all my old songs will be deleted, and I don't have any songs on my new computer. Is there any way I can use iTunes on my new computer without deleting all my songs?
And I'm not very good with computers, so if you could explain it simply, that would be fantastic.

If I update my iPhone 4 will i lose everything?

Hi, I have the iPhone 4 (not 4s) and haven't updated it basically since i got it around 2 years ago. I've always been worried about updating because once my friend updated hers and she lost all her contacts and messages, photos and everything and I'm really worried I'll lose stuff, there are messages on my phone that I'm quite sentimental about and really don't want to lose. I'm aware however that I'm going to have to find a way to do something soon as my phone has such an old iOS version i basically can't download or update any apps anymore as they're all on higher versions of iOS now. I'm just scared it'll delete everything like my friend's and I'll lose the sentimental messages.