What aspect ratio is and why you might change it
Aspect ratio is the width-to-height proportion of your screen or image. The most common ratios are 16:9 (widescreen, used on most modern monitors and TVs), 4:3 (older square-ish screens), and 21:9 (ultrawide). Changing aspect ratio stretches or squeezes what you see, or crops it to fit a different shape.
You might change aspect ratio because you're connecting an older monitor to a newer computer, recording video for a platform that needs a different shape (like Instagram Stories versus YouTube), or because your current display cuts off parts of what you're trying to see. Some games also run better or look better at different ratios depending on your hardware.
The steps differ depending on whether you're adjusting your monitor display, changing how a camera records, or resizing video in editing software. Each one lives in a different place in your system.
Key Takeaways
- Monitor aspect ratio is set in your graphics driver or display settings, not in Windows or macOS directly — the exact location depends on whether you use NVIDIA, AMD, or Intel graphics.
- Changing aspect ratio on a monitor may leave black bars on the sides or stretch the image, depending on whether you choose to scale or crop.
- Cameras and phones change aspect ratio in their settings menu, usually labeled as "photo size" or "video format" — the options available depend on your device's hardware.
- Video editing software like DaVinci Resolve or Adobe Premiere lets you change aspect ratio during export, which is the safest way to resize video without losing quality.
- Some aspect ratios are locked to certain frame rates or resolutions on your device, so you may not be able to use every combination.
Changing aspect ratio on a Windows monitor
On Windows, your graphics driver controls aspect ratio, not the operating system itself. The steps depend on which graphics card you have — NVIDIA, AMD, or Intel integrated graphics.
For NVIDIA graphics: Right-click on your desktop and select "NVIDIA Control Panel". Go to "Display" on the left, then "Adjust desktop size and position". Under "Scaling", you can choose "Aspect ratio" or "Full panel" (which stretches the image). If you choose aspect ratio, Windows will add black bars to the sides. Click "explore" and then "OK".
For AMD graphics: Right-click on your desktop and select "AMD Radeon Settings". Go to "Display" and look for "GPU Scaling" or "Scaling Options". Toggle GPU Scaling on, then choose your preferred scaling method. AMD usually offers "Maintain aspect ratio" (adds black bars) or "Full panel" (stretches). explore the change and restart if prompted.
For Intel integrated graphics: Right-click on your desktop and select "Intel Graphics Settings". Go to "Display" and find "Scaling". Choose between "Maintain aspect ratio" or "Scale full screen". explore and close the window. You may need to restart your computer for the change to take effect.
Changing aspect ratio on a Mac monitor
macOS handles aspect ratio through System Settings rather than a separate graphics driver. Click the Apple menu, then "System Settings" (or "System Preferences" on older versions). Go to "Displays".
You will see a list of available resolutions. Each resolution has its own aspect ratio built in — for example, 2560 × 1440 is 16:9, while 2560 × 1600 is 16:10. Select the resolution you want. If you want to force a non-native aspect ratio, you can hold the Option key while clicking "Scaled" to see additional resolutions that your Mac can simulate, though this may reduce sharpness.
If you are connecting an external monitor, the same process applies — go to Displays in System Settings and choose from the available resolutions. macOS automatically detects what your monitor supports.
Changing aspect ratio on a camera or phone
Most cameras and phones let you choose aspect ratio before you take the photo or video. The exact location varies by device, but it is usually in the camera app's settings.
On iPhones: Open the Camera app. At the top of the screen, you will see aspect ratio options like 16:9, 4:3, or 1:1 (square). Tap the one you want. The preview will update to show you what the photo will look like in that shape. This setting applies to photos only — video aspect ratio is controlled separately in the camera settings.
On Android phones: Open your camera app (the exact name depends on your phone's manufacturer). Look for a settings icon (usually a gear) and tap it. Find "Photo size" or "Aspect ratio" and select your preferred option. Some phones also let you tap an aspect ratio button directly in the viewfinder without opening settings.
On dedicated cameras: Look in the menu for "Image Size", "Photo Format", or "Recording Format". The available options depend on your camera model. Some cameras lock certain aspect ratios to specific frame rates — for example, you might only be able to shoot 4K video in 16:9, not in 21:9.
Changing aspect ratio in video editing software
If you have already recorded video and want to change its aspect ratio, do this during export rather than trying to resize the original file. This gives you the most control and the best quality.
In DaVinci Resolve: Open your project. Go to the "Deliver" tab on the right. Under "Video", find "Resolution". You can change the width and height here to any aspect ratio you want. DaVinci will automatically letterbox (add black bars) or crop the video to fit. Choose your export format and click "Add to Render Queue", then "Start Render".
In Adobe Premiere: Go to "File" > "Export" > "Media". In the export dialog, find "Video" settings. Look for "Basic Video Settings" and change the width and height to your desired aspect ratio. Premiere will show you a preview of how the video will look. Click "Export" to save the file.
In free software like Shotcut: Open your video. Go to "File" > "Export Video". In the export panel, find "Video Mode" and select your desired resolution and aspect ratio from the dropdown. Shotcut includes common presets like 16:9, 4:3, and 1:1. Click "Export" to save.
Understanding black bars, stretching, and cropping
When you change aspect ratio, your system has to decide what to do with the space that does not fit. There are three common approaches: letterboxing (black bars), pillarboxing (black bars on the sides), and stretching.
Letterboxing adds black bars on the top and bottom when you change from a wider ratio to a narrower one. For example, if you export 16:9 video as 4:3, you get black bars above and below. This preserves the original image without distortion.
Pillarboxing adds black bars on the left and right when you change from a narrower ratio to a wider one. This also preserves the original image without distortion.
Stretching distorts the image to fill the entire space without black bars. This is rarely what you want — it makes people look wider or narrower than they actually are. Avoid it unless you have a specific reason.
Cropping cuts off the edges of the image to fit the new aspect ratio. This loses information but does not distort what remains. Some video editing software offers this as an option during export.
Aspect ratio limitations and compatibility
Not every aspect ratio works with every resolution or frame rate on your device. Your camera or monitor may only support certain combinations.
For example, some phones can shoot 4K video only in 16:9, not in 21:9. Some older monitors support 4:3 aspect ratio only at lower resolutions like 1024 × 768, not at higher ones. Check your device's manual or specifications to see which combinations are available.
If you try to set an aspect ratio that your hardware does not support, your device will either ignore the change or fall back to the nearest supported option. This is not a problem — it just means you have fewer choices than you might expect.
Frequently Asked Questions
Will changing aspect ratio make my monitor blurry?
Only if you choose a resolution that is not native to your monitor. Native resolution is the one your monitor was designed for — usually printed on the box or in the manual. If you force a different resolution, the image will look softer or pixelated. Stick to resolutions marked "recommended" or "native" in your display settings.
Can I change aspect ratio without black bars?
Only if your monitor or video natively supports that aspect ratio, or if you are willing to crop the image. If you are connecting a 4:3 monitor to a 16:9 graphics card, you will get black bars unless you stretch the image (which distorts it). Cropping removes the bars but also removes part of what you are trying to see.
What aspect ratio should I use for social media video?
It depends on the platform. YouTube and TikTok prefer 16:9 for desktop and 9:16 for mobile. Instagram Stories use 9:16. Facebook accepts most ratios but recommends 1:1 (square) or 4:5. Check the platform's help documentation for the exact specifications before you export.
Why does my camera only offer certain aspect ratios?
Your camera's sensor has a fixed physical size and shape. The aspect ratios it offers are the ones that use the sensor efficiently without wasting pixels. Adding aspect ratios that do not match the sensor would require cropping, which reduces image quality. Manufacturers choose the ratios that work best with their hardware.
Can I change aspect ratio after I have already recorded video?
Yes, but you should do it in video editing software during export, not by resizing the original file. Resizing the original file may reduce quality. Export software like DaVinci Resolve or Premiere lets you change aspect ratio without touching the original recording.