iPad browser WIDTH & HEIGHT standard
The pixel width and height of your page will depend on orientation as well as the meta viewport tag, if specified. Here are the results of running jquery's $(window).width() and $(window).height() on iPad 1 browser.
When page has no meta viewport tag:
- Portrait: 980x1208
- Landscape: 980x661
When page has either of these two meta tags:
<meta name="viewport" content="initial-scale=1,user-scalable=no,maximum-scale=1,width=device-width">
<meta name="viewport" content="initial-scale=1,user-scalable=no,maximum-scale=1">
- Portrait: 768x946
- Landscape: 1024x690
With <meta name="viewport" content="width=device-width">:
- Portrait: 768x946
- Landscape: 768x518
With <meta name="viewport" content="height=device-height">:
- Portrait: 980x1024
- Landscape: 980x1024
With <meta name="viewport" content="height=device-height,width=device-width">:
- Portrait: 768x1024
- Landscape: 768x1024
With <meta name="viewport" content="initial-scale=1,user-scalable=no,maximum-scale=1,width=device-width,height=device-height">
- Portrait: 768x1024
- Landscape: 1024x1024
With <meta name="viewport" content="initial-scale=1,user-scalable=no,maximum-scale=1,height=device-height">
- Portrait: 831x1024
- Landscape: 1520x1024
There's no simple answer to this question. Apple's mobile version of WebKit, used in iPhones, iPod Touches, and iPads, will scale the page to fit the screen, at which point the user can zoom in and out freely.
That said, you can design your page to minimize the amount of zooming necessary. Your best bet is to make the width and height the same as the lower resolution of the iPad, since you don't know which way it's oriented; in other words, you would make your page 768x768, so that it will fit well on the iPad's screen whether it's oriented to be 1024x768 or 768x1024.
More importantly, you'd want to design your page with big controls with lots of space that are easy to hit with your thumbs - you could easily design a 768x768 page that was very cluttered and therefore required lots of zooming. To accomplish this, you'll likely want to divide your controls among a number of web pages.
On the other hand, it's not the most worthwhile pursuit. If while designing you find opportunities to make your page more "finger-friendly", then go for it...but the reality is that iPad users are very comfortable with moving around and zooming in and out of the page to get to things because it's necessary on most web sites. If anything, you probably want to design it so that it's conducive to this type of navigation.
Make boxes with relevant grouped data that can be easily double-tapped to focus on, and keep related controls close to each other. iPad users will most likely appreciate a page that facilitates the familiar zoom-and-pan navigation they're accustomed to more than they will a page that has fewer controls so that they don't have to.