Let's use the example of an iPhone 7 Plus.

#### Step One

If we wanted to know how many inches the display of an iPhone 7 Plus is, we'd have to know it's PPI.

In this case, according to Apple's specifications, it's 401 PPI.

#### Step Two

Then, we'll need to know the pixel measurements in both width and height. The iPhone 7 Plus is 1080 pixels by 1920 pixels.

#### Step Three

Therefore, our equation would be:

1080 (pixels) / 401 (PPI) = 2.7 inches (rounded up from 2.69)

1920 (pixels) / 401 (PPI) = 4.8 inches (rounded up from 4.78)

So, an Apple iPhone 7 Plus will be 4.8 inches in height by 2.7 inches in width.

In fact, if you own an iPhone 7 Plus, pull it out, grab some measuring tape, and see for yourself!

### Inches to Pixel Example

Let's say you have a printed image (maybe a photograph) and want to know what the pixels would be when scanned.

#### Step One

Let's say the image is 8.5 inches by 11 inches, which is the standard size of a typical piece of printer paper.

Let's say that you also know the DPI of the printer used to print the photo is 600 DPI.

#### Step Two

Our equation would be:

8.5 (inches) x 600 (DPI) = 5,100 pixels

11 (inches) x 600 (DPI) = 6,600 pixels

Therefore, your scanned image of the photograph would be 5,100 pixels by 6,600 pixels.