Change Aspect Ratio in OBS: A Practical Guide

Updated 9 November 2026 · Standard formula, shown below

To change the aspect ratio in OBS Studio, adjust the canvas resolution in Settings and, if needed, resize or crop each source to fit. The canvas controls the shape of the video OBS produces; changing it does not automatically change a camera, game, or other source’s own shape.

What aspect ratio means in OBS

Aspect ratio describes the relationship between an image’s width and height. A 16:9 image is wider than it is tall, while 9:16 is a vertical format. OBS Studio uses a video canvas as the layout area for scenes, then scales that canvas to the output resolution used for streaming or recording.

For example, a canvas of 1920 × 1080 pixels has a 16:9 ratio. A canvas of 1080 × 1920 is 9:16. The first number is width; the second is height. The ratio can be simplified by dividing both numbers by the same value.

Changing the canvas is useful when making a vertical video, matching a nonstandard display, or producing a video in a format different from the source footage. It can also affect existing scenes, so check how each source appears after the change.

Change the canvas aspect ratio

Open OBS Studio and select Settings.
Choose Video in the settings sidebar.
Change Base (Canvas) Resolution to the width and height you want. For example, enter 1080 horizontally and 1920 vertically for a 9:16 canvas.
Review Output (Scaled) Resolution. Set it to the intended exported or streamed dimensions, or leave it at a suitable landscape or portrait resolution matching your canvas.
Select Apply, then OK. Inspect your scenes in the preview and reposition or resize sources as needed.

The Base (Canvas) Resolution is the workspace OBS uses to arrange scene elements. Output (Scaled) Resolution determines the dimensions of the encoded video. If the two resolutions use different aspect ratios, OBS must scale or crop the image to reconcile them, and the result may not look as expected. For straightforward results, use matching ratios for the canvas and output.

Fit, stretch, or crop a source

A source may retain its original proportions when placed on a canvas with a different ratio. Select the source in the preview or Sources list, then use the transform options to control its framing. Right-click the source and open Transform for available actions, including fit-to-screen and stretch-to-screen. Menu wording may vary slightly by OBS version or source type.

Fit to screen: scales the entire source so it fits inside the canvas without changing its proportions. Empty space can remain along the sides or top and bottom.
Stretch to screen: fills the canvas but can distort the image by changing its proportions. Faces and circles may look unnaturally wide or tall.
Crop to fit: fills the canvas while cutting off parts of the source. Hold Alt while dragging a source edge in the preview to crop it in many OBS setups; check the resulting frame carefully.

Another option is to resize a source while preserving its proportions, then position it manually. This is often preferable to stretching when you want the complete image visible. For a webcam over gameplay, for instance, keep the gameplay filling the canvas and scale the webcam as a separate overlay.

Choose resolutions for landscape and portrait

Pick the intended shape before arranging a complex scene. Common examples include:

16:9 landscape: 1920 × 1080 or 1280 × 720.
9:16 portrait: 1080 × 1920 or 720 × 1280.
4:3: 1440 × 1080 or 1024 × 768.
1:1 square: 1080 × 1080.

These are examples, not requirements for every platform or recording. Confirm the dimensions and orientation needed for your destination, then choose a resolution that your computer and recording or streaming setup can handle. A larger pixel count can require more processing and storage; changing the aspect ratio alone does not guarantee better quality.

OBS scenes can be reused with a different canvas, but their layouts may need substantial adjustment. Text, borders, browser sources, and overlays positioned near the edges are especially likely to need repositioning. If you produce both portrait and landscape videos, separate scene collections or carefully arranged alternate scenes can make switching formats easier.

Common problems and how to fix them

Black bars appear: The source and canvas have different aspect ratios, and the source is being fit rather than cropped. Choose whether to keep the full image with bars or crop the edges to fill the frame.
The picture looks stretched: A transform or output setting is forcing one ratio into another. Restore proportional scaling, then fit or crop the source instead of stretching it.
Part of the source is missing: Check for an existing crop, and use Transform options such as resetting the transform before arranging it again.
The recording has unexpected dimensions: Recheck both resolution fields under Settings > Video. The canvas and scaled output are separate settings.
Only one source changes: Source transforms apply to the selected source, while the canvas change affects the whole scene layout. Select the intended source before resizing or cropping.

Also distinguish a canvas change from changing a display’s resolution. OBS controls the video composition and output; it does not change the physical shape of a monitor or camera sensor.

Frequently Asked Questions

How do I make OBS vertical?
Set Base (Canvas) Resolution to a portrait size such as 1080 × 1920 under Settings > Video, then choose a matching Output (Scaled) Resolution and rearrange the scene.

Will changing the aspect ratio stretch my webcam?
Not necessarily. The canvas change does not by itself mean every source is stretched, but a source can look distorted if you use a stretch transform. Fit it proportionally or crop it instead.

What is the difference between Base and Output resolution?
Base (Canvas) Resolution is the scene’s layout size. Output (Scaled) Resolution is the size of the encoded video. Matching their aspect ratios avoids unwanted scaling or cropping.

Can OBS record in a different aspect ratio from my monitor?
Yes. Set the canvas and output to the desired video shape, then frame the display or capture source within that canvas. Depending on the source ratio, you may need bars, cropping, or a smaller fitted image.

Why do my scenes look different after changing the canvas?
Scene elements keep their transforms and positions, but the usable frame has changed shape. Review each scene and reposition, resize, or crop its sources for the new dimensions.

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.