— Dane Creek

How Big Can I Print?

When working with photographers on prints the most common question I get is “how big can I print my photo”? There’s a lot of confusion around this and I figured I’d take a moment to walk through the basics.

First and foremost we need to get terms straight:

  • dpi (dots per inch): this term is completely useless and irrelevant when it comes to working with digital images and prints. Banish it from your brain. Never speak it again.
  • ppi (pixels per inch): this is the number that matters. It tells you how many pixels from your image will get crammed into each inch of physical output.

To figure out how big a print you can do you need to know what ppi is required to make a good looking print. There are a lot of opinions about this on the Internet. You’ll see people argue about whether you should print at a “native resolution” for the printer. You’ll see varying numbers depending on how far away people will stand from the final print. You’ll even see different numbers thrown out depending on what type of print medium is used.

So what ppi should you use? We keep it simple and stick with 300 ppi for most jobs*. In our experience it allows for reasonable size prints from most DSLR files.

Once you know the ppi you should target it’s basic math to determine how big your print can be. Let’s say your digital file is 2400 x 3000. Just divide by 300 and you get an image size of 8×10”. Easy!

What happens if you want to go bigger than what the math shows? You need to add more pixels to your image. There are a lot of ways to do that: Lightroom’s print resizing, Photoshop’s image size dialog, Perfect Resize 7 (a.k.a. Genuine Fractals), etc. Regardless of the software used you basically tell it how big a physical image you plan on doing, how many pixels per inch are required, and the software will make up additional pixels to give you a big enough file to print.

In our experience, assuming you are starting with a photo that has good quality pixels, Lightroom’s default image sizing on print works just fine for images down to about 150 ppi. Upsizing from a resolution lower than that starts to get into using the magic of 3rd party applications.

Hopefully this helps clear up some of the confusion around this topic. If you have any questions feel free to leave them in the comments question below and we’ll do our best to answer them.

* If you have your own printer and are extremely detail-oriented you can do test prints at various ppi values and look for the one that gives you the highest observable detail in the resulting print.