Instagram Stories display at 1080 x 1920 pixels in a 9:16 vertical aspect ratio. Reels use the same dimensions. If you upload a 16:9 landscape video (the default from most cameras), Instagram will either letterbox it (adding large bars above and below, wasting 44% of the screen) or auto-center-crop it, often cutting off important parts of the frame.
Neither option is ideal. The better approach is to manually crop the video yourself, choosing which part of the frame to keep so the important content stays visible.
The math behind 16:9 to 9:16 cropping
A 1920x1080 landscape frame has an aspect ratio of 16:9. Instagram's 9:16 format is the exact inverse. To convert between them, you need to extract a vertical strip from the horizontal frame.
The widest vertical crop you can take from a 1080p landscape frame is 607 pixels wide by 1080 pixels tall (which maintains 9:16). That 607-pixel-wide strip represents only about 31.6% of the original 1920-pixel width. You are discarding roughly 68% of the horizontal content.
This is why crop positioning matters. If your subject is centered, a center crop works. If the subject is on the left or right third of the frame, you need to offset the crop region accordingly.
Three strategies for landscape-to-vertical conversion
Strategy 1: Center crop. This works when the subject is in the middle of the frame. Set your crop to 9:16 and center it. This is the fastest approach and works for talking-head videos, centered product shots, and interviews where the subject sits in the middle.
Strategy 2: Dynamic reframing. For videos where the subject moves across the frame, a single static crop will not work well. You would need to use a video editor with keyframe-based crop positioning, which is beyond what a simple crop tool does. For static-subject clips, this is not needed.
Strategy 3: Letterbox with blurred background. Instead of cropping, scale the entire 16:9 video to fit the width of the 9:16 frame and fill the empty space above and below with a blurred, zoomed version of the video itself. This preserves 100% of the original content while looking more polished than plain black bars. Some editors call this "fill blur" or "background blur." MediaBrew's resize tool with the TikTok/Instagram preset applies this strategy.
What to keep in the crop zone
When choosing where to place your crop region, prioritize:
- Faces. Human faces drive engagement. If a face is in the frame, make sure it is fully within the crop area with some headroom above.
- Text and captions. If your video has burned-in text (lower thirds, titles, subtitles), make sure they fall within the crop boundaries.
- Key action. If someone is demonstrating something with their hands, the hands need to be in frame.
- Product. For product videos, center the product in the crop zone.
Optimal resolution for Instagram after cropping
After cropping to 9:16, your output should be at least 1080 pixels wide. Instagram will accept lower resolutions but will upscale them, which introduces blurriness. If your source is 1080p landscape and you crop a 607x1080 vertical strip, you should upscale the output to 1080x1920 for best results on Instagram.
If your source is 4K (3840x2160), your 9:16 crop from the frame gives you a 1215x2160 strip, which is already above Instagram's requirements. You can resize to 1080x1920 for an optimal file.
If your source is 4K (3840x2160), your 9:16 crop from the frame gives you a 1215x2160 strip, which is already above Instagram's requirements. You can resize to 1080x1920 for an optimal file. The MediaBrew crop tool has a 9:16 preset that snaps the overlay to the correct ratio. Position it over your subject, crop, and download the result ready for upload.