How Big is a 12 Megapixel Photo?

Rumors claim that Apple will introduce a new iPhone model in September with a 12 megapixel camera. Aside from "that's more megapixels!" exactly what will a 12 megapixel camera in your next iPhone get you? Read on to see Jeff Gamet's explanation.

Your next iPhone could have a 12 megapixel camera. Is that a big deal?Your next iPhone could have a 12 megapixel camera. Is that a big deal?

What's a Megapixel?

A megapixel is a million pixels, and each pixel makes up a single point in your photographs. That means an 8 megapixel camera, like the one used in the iPhone 6 and iPhone 6 Plus captures images with 8 million pixels. The rumored iPhone 6s and its 12 megapixel camera will snap photos that are packed with 12 million pixels.

More is Better, Right?

When it comes to megapixels, more isn't necessarily better. It's certainly bigger, but that doesn't equate to better. Instead, it's the camera lenses and the quality of the sensor that captures light to convert into your photos. An 8 megapixel photo from a high quality lens and sensor combo will look much better than the same photo from a 12 megapixel image shot with mediocre lenses and sensors.

How Big is a 12 Megapixel Photo?

Let's start with the iPhone 6's 8 megapixel photos for a little comparison. In this case, image sizes are measured in pixels multiplied together. An 8 megapixel image is 3456 pixels wide and 2304 pixels tall. When you multiply the two numbers together you get your overall megapixel size; in this case, that's 8.

A 12 megapixel image is 4000 pixels wide and 3000 pixels tall. That's definitely bigger, but without some context it doesn't mean much. Let's look at some real world photo uses to put the comparison into perspective.

These numbers are what I'd call the high end of acceptable, or potential maximum image sizes. Go larger, and your images will start to get that jaggy pixelated look.

8 megapixel Wide (inches) Tall (inches)
72 PPI screen 48 32
144 PPI (Retina) 24 16
150 PPI photo print 23 15.4
300 PPI professional print 11.5 7.7


12 megapixel Wide (inches) Tall (inches)
72 PPI screen 55.6 41.7
144 PPI (Retina) 27.8 20.85
150 PPI photo print 36.7 20
300 PPI professional print 13.3 10


Since I like to see the best print quality possible, I try to stay below the high end for image sizes. There isn't, however, anything stopping you from printing a photo at a larger size; just remember the larger you go the lower the overall image quality will be.

Will the Next iPhone take Better Photos than the iPhone 6?

That gets us to the big question: Will iPhone photos taken with a 12 megapixel camera be better than those taken with an 8 megapixel iPhone camera? The answer to that is a definite maybe.

Assuming Apple uses the same lenses and a sensor that doesn't offer overall better light capture, then the next iPhone will offer bigger photos and not better photos. Assuming the 12 megapixel sensor Apple uses is better—and the optics get an upgrade, too—then your next iPhone will snap overall better photos.

What you won't get, no matter what camera upgrades the next iPhone offers, will be a fix for weak photography skills. Apple still hasn't figured out how to keep your fingers out of your shots, or to put heads back when they're cut off at the top of a pic. You're still on your own for those.