If you've been using Midjourney, you've likely seen prompts that include “–ar” followed by a number, colon, and another number. But what the heck does it mean?!
Read our post about using repetition in Midjourney, too.
Aspect Ratios in Midjourney
The “–aspect” or “–ar” parameter is responsible for changing the shape of the picture you make.
This shape is called the “aspect ratio,” and it's just the proportion of how wide and tall the picture is.
You might see an aspect ratio written like this: 7:4 or 4:3, where the first number is how wide the picture is and the second number is how tall it is.
I always forget which is which… so I have some aspect ratios saved in my AI notion board.
When a picture has the same width and height, it's called a “square” picture, and its aspect ratio is 1:1.
For example, a square picture could be 1000 pixels wide and 1000 pixels tall, or it could be 1500 pixels wide and 1500 pixels tall.
A computer screen might have a different aspect ratio, like 16:10, which means the picture is 1.6 times wider than it is tall. So a picture with a 16:10 aspect ratio could be 1600 pixels wide and 1000 pixels tall, or 4000 pixels wide and 2000 pixels tall, or 320 pixels wide and 200 pixels tall, and so on.
The most popular aspect ratios I personally use are 2:3 and 3:2 because I mostly design for blog post images and journals.
–ar 1:1 is the default aspect ratio. This will create a square output with all sides being equal.
–ar 5:4 is a common print ratio
–ar 3:2 is a common print ratio
–ar 2:3 is a common print ratio
–ar 7:4 is the closest to TV and smartphone screens.
Here are some examples of those ratios in action. The base prompt being beautiful field of colorful tulips.
When creating blog posts, I like to do a mix of 3:2 and 2:3 aspect ratios. Taller photos (2:3 ratio) are great for Pinterest, and they align well if you're using columns… like this:
Add a little text in Canva and you're good to go for pins! 🙂
How to Add Aspect Ratio Parameter
It's super easy to add the aspect ratio parameter to your Midjourney prompts. I do it at the very end (and then Midjourney automatically adds in the –v 5 or whatever version you're using – adjust in /settings if you want to change that).
This screenshot is from my Midjourney server. Notice they are landscape photos, so I used the aspect ratio 3:2. I can make them vertical by swapping the numbers and making it –ar 2:3
Oh, and YES you can do other ratios… like if you want to create bookmarks:
It doesn't always work perfectly; I've gotten some weird grid things going on with a few of the outputs. But for the most part, they're pretty awesome.
Let us know in the group which aspect ratios are your favorites.