# How to change the aspect ratio in Premiere Pro

> Change the aspect ratio in Premiere Pro with a new sequence and a new Frame Size, or with Auto Reframe Sequence. Exact clicks, sizes for 9:16, 1:1 and 4:5.
- **Author**: Marxx
- **Published**: 2026-11-10
- **Category**: Video editing
- **URL**: https://marxx.ai/library-guides/how-to-change-aspect-ratio-in-premiere-pro

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In Premiere Pro (now called Adobe Premiere), choose File > New > Sequence, open the Settings tab and type a new Frame Size under Video, or run Sequence > Auto Reframe Sequence to make a reframed copy.

## Route 1: a new sequence

1. Choose **File > New > Sequence**.
2. Open the **Settings** tab of the New Sequence dialog.
3. Under Video, type the Frame Size: horizontal first, then vertical. Premiere shows the aspect ratio.
4. Name the sequence and select **OK**.
5. Bring in your clips. Move and scale each one so the subject sits inside the new frame.

Adobe's page covers new sequences only. It does not say how to change the size of a sequence you have already built. For that, use Route 2.

## Route 2: Auto Reframe

1. Select the sequence in the Project panel, then choose **Sequence > Auto Reframe Sequence**.
2. Pick a Target Aspect Ratio from the presets, or enter a custom ratio. You can also enter a custom Resolution. Changing the resolution changes the aspect ratio to match.
3. Pick Motion Tracking: Slower Motion, Default or Faster Motion.
4. Optional: tick Clip Nesting to keep keyframes or speed changes.

Premiere makes a duplicate sequence in the Auto Reframe Sequences folder at the root of the Project panel. Every clip carries the Auto Reframe effect.

## Sizes to type

| Ratio | Frame Size | Check |
|---|---|---|
| 9:16 | 1080 x 1920 | 1080 / 1920 = 0.5625, which is 9:16 |
| 4:5 | 1080 x 1350 | 1080 / 1350 = 0.8, which is 4:5 |
| 1:1 | 1080 x 1080 | Equal sides |
| 16:9 | 1920 x 1080 | 1920 / 1080 = 1.78, which is 16:9 |

Meta recommends 1440 x 2560 for Reels and Stories ads and 1440 x 1800 for Facebook Feed (checked 3 Nov 2026). Both keep the same ratios as the 1080 sizes above. Adobe's export pages name no vertical preset, so the size comes from your sequence.

## A worked example

Say you edited a 1920 x 1080 ad and now need a 4:5 copy for Facebook Feed. Type 1080 and 1350 into the Frame Size. Premiere shows 4:5, because 1080 divided by 1350 is 0.8. You confirm the ratio before you press OK, then re-place any text so it sits inside the new frame.

## Mistakes to avoid

- Typing the vertical size in the horizontal box, which makes a landscape sequence
- Forgetting to re-place text after the ratio changes
- Changing the size, then exporting at the old size

## Where Marxx fits

[Marxx's AI video editor](/features/ai-video-editor) reframes for another placement in one request, and exports an editable timeline for Premiere Pro. We make Marxx. Plans start at $9 a month at launch prices (checked 3 Nov 2026).

For the pixel maths behind a vertical crop, see [how to convert a 16:9 video to 9:16](/guides/how-to-convert-16-9-to-9-16). To keep the whole frame, see [how to resize a video for Instagram without cropping](/guides/how-to-resize-video-for-instagram-without-cropping). Premiere is a subscription app, with plans in [Premiere Pro pricing](/prices/premiere-pro-pricing).

## FAQ

### Can I change the aspect ratio of an existing sequence?

Adobe's help page covers new sequences. For an edit you have already built, Auto Reframe Sequence makes a copy at the new ratio.

### Does Auto Reframe work on every clip?

It reframes every clip in the sequence. Choose Slower Motion, Default or Faster Motion to set how quickly it follows the subject. Check the result clip by clip.

### Which ratio should I pick for Reels?

9:16. Meta recommends 9:16 for Reels ads (checked 3 Nov 2026). See [9:16 vs 4:5 video ads](/compare/9-16-vs-4-5-video-ads).

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