What is the best size for an Instagram collage?

Use 1080 × 1350 pixels (4:5) for a feed post. It takes up the most space in the feed. Use 1080 × 1920 pixels (9:16) for stories and reels.

What size is a 4 × 6 print in pixels?

At 300 dpi, a 4 × 6 inch print is 1200 × 1800 pixels. That is a 2:3 shape.

Instagram crops feed posts that are taller than 4:5 or wider than 1.91:1. Make the collage in 4:5 or 1:1 to avoid cropping.

A great collage in the wrong size gets cropped. Faces get cut off and text disappears off the edge. Here is every size you need, in one place.

In CollageFlow, you pick the shape and the app handles the pixels. The options are 1:1, 4:5, 9:16, 16:9, 3:4, 4:3, 2:3, and 3:2.

Feed posts: use 4:5. A tall post takes up more of the screen than a square one. More screen means more attention.

Stories and reels: use 9:16. Keep important text away from the top and bottom 250 pixels. Instagram puts your name and buttons there.

Carousels: every slide uses the shape of the first one. Pick 4:5 for all of them.

Use 9:16 at 1080 × 1920. Keep text in the middle. The caption covers the bottom and the buttons cover the right side.

Use 2:3 at 1000 × 1500. Taller pins get cut off in the feed. A clear title on the image helps people decide to tap.

4:5 works well in the feed, just like on Instagram. For a cover photo, a wide 16:9 shape is safer.

For prints, the shape matters more than the exact pixels. Make the collage in the same shape as the paper.

Export at the highest quality the app allows. Aim for 300 pixels per inch for sharp prints.

Making a square collage for a story. It will sit in the middle with big empty bars.
Putting text near the edges. Apps put buttons there. Keep a safe margin.
Changing the size at the end. Choose the size first. Changing it later can move everything around.