In the graphic design world, there’s a lot of talk about DPI and PPI. But what do those acronyms stand for? What’s the difference between them? And most importantly, what do they mean for your final product?
This article will break it all down for you. So whether you’re a seasoned pro or just starting in the field, read on for our guide on PPI vs. DPI.
PPI vs. DPI: What’s the Difference?
If you’ve been designing for any amount of time, you’ve undoubtedly heard the acronyms DPI and PPI — they’re used often when describing image size and quality. The problem is the two are often used interchangeably when they are two very different things.
At its simplest, PPI stands for Pixels Per Inch, while DPI refers to Dots Per Inch. PPI measures the pixel density of an image file or how many pixels are contained in one square inch of the image. DPI measures the printing resolution of a printer or the number of dots of ink that can be printed in one square inch. If that’s confusing, don’t worry — we’ll explore these differences in much greater detail below.
In the world of digital design, PPI is more important than DPI. That’s because PPI is a measure of the pixels in your digital images, while DPI is a measure of the printer’s resolution. In other words, PPI is a property of your image, while DPI is a property of your printer. As long as your image file has enough pixels, it will print clearly, regardless of the DPI of your printer.
What is PPI?
As we mentioned, PPI stands for Pixels Per Inch. Pixels are the individual dots of color that make up your image onscreen. The PPI of an image is the pixel count or quantity of pixels contained within one square inch of the image.
In other words, PPI is a way to measure the resolution or density of pixels. A higher PPI means more pixels, and more pixels means a higher resolution. A lower PPI means fewer pixels, and a lower resolution.
The PPI of an image is important because it determines how clear or blurry an image will appear when printed. A low PPI (say, 72 PPI) will result in a blurry, pixelated image when printed. Viewers may notice individual pixels. A high PPI (300 PPI or higher) will produce a clearer image.
When to Use PPI
Use PPI when working with images, like digital photographs and raster images and illustrations. It’s most useful when preparing images for printing. Higher PPI images of 300 PPI or more will print best.
PPI isn’t really important when preparing images for the web since monitors have fixed pixel density. For this reason, it’s best to save images with a lower PPI (72 PPI is standard) to keep file sizes smaller.
Now, this is the part of the article when you say, “But I’ve been saying 72 DPI and 300 DPI all along, and now you’re telling me that’s the wrong terminology?”
Yes. The correct terminology is PPI, not DPI. But, as we mentioned above, most people use the two interchangeably. So, when you say “300 DPI” everyone knows what you mean. However, if you want to be correct, start saying “300 PPI” instead.
Part of the confusion between the two comes because printers use the term DPI (we’ll explain it next), and image editing programs have a DPI setting to make the conversion for print easier. The unintended consequence was that it made users start saying the two acronyms interchangeably!
(As a side note, “Typeface” and “Font” are also two different things, but we can thank Microsoft for making them interchangeable in modern vernacular, too! You can read all about that in our Typeface vs. Font guide.)
How to Change PPI
Changing the PPI of an image to make it a larger size is known as “resampling.” This is the process of adding additional pixels to an image. Adding pixels to an image can result in a loss of image quality because the software is “guessing” what the pixel should look like based on the pixels around it. Until very recently, this was not advised because the results were so bad.
However, AI technology has finally made it possible to increase the PPI of an image with some impressive results. To increase your PPI, use a dedicated program — like Topaz Gigapixel AI, Adobe Photoshop’s Super Resolution, or Remini Image Upscale. Simply changing the size of your image with your image editor could result in unintended, unwanted results.
If you want to reduce the size of your image and decrease the PPI, that’s quite a bit easier. You can simply downsize the image using your preferred image editor’s resize function, and you’ll still have a quality image.
What is DPI?
DPI stands for Dots Per Inch. During the printing process, your printer deposits tiny droplets of ink (or toner) onto the sheet of paper when you print an image. The number of those droplets per inch is referred to as DPI. DPI has nothing to do with your images and everything to do with the resolution of the actual printer.
It takes several ink dots to create one single pixel, which is why PPI and DPI can’t be used interchangeably.
Every printer has its own DPI. A basic inkjet printer varies from 300 to 720 DPI. Laser printers are 600 to 1200 DPI. Some photo printers go as high as 2,400 DPI or more. And professional color printers can go even higher than that.
When to Use DPI
DPI is a term used for printing. If your image will be printed, the printer will use it. Unlike PPI, a higher DPI does not necessarily mean high-quality prints. This is because there’s no standard dot size or shape — they vary greatly from one printer to the next. DPI will rarely come into the discussion unless you’re communicating with a print company about their equipment.
It’s important to understand by this point, that when someone tells you they need a “300 DPI image” what they really need is a 300 PPI image. They’re using the term interchangeably (and incorrectly, as you’ve just learned). This request is also useless without including the image size, too.
Frequently Asked Questions
PPI and DPI are often used interchangeably but they are two very different things. PPI is the digital image resolution — the number of pixels per square inch in your images or digital photos. And DPI is the print resolution — the number of dots that your printer will use to print one inch of your image.
The PPI you should scan your photos at depends on how you’re going to use the digital files. If you’re just going to view them on your display screen, 72 PPI is plenty. If you’re going to print them, 300 PPI is standard.
300 PPI is standard for printing photos with good print quality. 300 PPI gives you enough detail that your photos will look sharp and clear.
You can’t convert digital images to 300 PPI, but you can resample them. Resampling is the process of adding or removing pixels for resizing images. See our section above entitled “How to Change PPI.”
Inches to Pixels Reference Chart
We’ve mentioned that saying you need a “300 PPI” image is useless if the final print’s physical size isn’t included. So how do you know if you’ve got enough pixels to export your image at 300 DPI to print it at the size you need?
It requires a little bit of math. To determine the pixel size of an 8″x10″ image, you would do the equation 8×300=2400 and 10×300=3000. So your image size needs to be 2400 x 3000 pixels to print 8″x10″ at 300 PPI.
You can find online pixel calculators to do the pixel count math for you, and we’ve created this handy chart with some common print sizes and their corresponding pixel dimensions:
|Image Size||Pixel Size at 300 PPI|
Final Thoughts on PPI vs. DPI
We hope this guide has helped clear up any confusion you may have had about PPI vs. DPI. Remember, PPI is the number of pixels per inch in your image, and DPI is the resolution of your printer. However, the term DPI is misused so often when the person actually means PPI, that the two terms have become interchangeable.
For example, when someone asks you for a “300 DPI image” what they really need is a 300 PPI image at the final print size. But if you still say 300 DPI, everyone will know what you mean. Because, at the end of the day, the semantics are far less important than understanding how to save a file properly so that you end up with the best quality print.