The 4:5 grids roll out and all videos are being consolidated into Reels. Questions about sizing? Save this for future reference.

1080 x 1350 for Static Feed Posts + Carousels
1080 x 1920 for Reels and Video Posts (now called Reels)
1080 x 1920 Reels + IG Live Covers
1080 x 1920 Instagram Stories
1080 x 1920 Slide Backgrounds for IG Lives
Any Size for Highlight Covers