What is the screen size of the original iPhone in inches?

The original iPhone had a 3.5-inch screen.

Apple’s first-generation iPhone used a 3.5-inch diagonal LCD display with a 320-by-480-pixel resolution and a 3:2 aspect ratio. It supported multi-touch input, allowing users to interact with the phone through gestures such as tapping, scrolling and pinching rather than relying on a physical keyboard or stylus.

When Steve Jobs introduced the iPhone on January 9, 2007, the screen was one of its most distinctive features. At the time, many smartphones used smaller displays alongside physical keyboards or navigation buttons. Apple instead made the touchscreen the central interface and kept the number of hardware buttons very small.

The original iPhone’s 3.5-inch size remained associated with early iPhone design, but later models grew considerably. The 4.7-inch display belongs to later iPhone generations, while 5-inch screens were not used on the first-generation model. Screen measurements are taken diagonally, from one corner to the opposite corner.