Change aspect ratio before you start editing

The fastest way to set aspect ratio in DaVinci Resolve is to choose it when you create a new project, not after you've already edited. When you open DaVinci Resolve and click New Project, a dialog box appears with a Master Settings section. In that section, you'll see a dropdown labeled Resolution. Click it and select the aspect ratio you need — 16:9 for widescreen, 4:3 for standard, 1:1 for square, 9:16 for vertical video, or 21:9 for ultrawide.

If you don't see the exact ratio you want in the preset list, scroll down to the bottom of that dropdown and select Custom. A new window opens where you can type in any width and height you need. For example, if you want 2.39:1 (cinema), you could enter 2390 by 1000. Once you've set it, click Save and your project will use that ratio for every clip you bring in.

Setting it at the start matters because DaVinci Resolve doesn't automatically resize or reframe clips to match a new project ratio if you change it later. You can change it, but your footage won't adjust — you'll have to manually fix each clip, which takes much longer.

Key Takeaways

  • Set aspect ratio when you create a new project by clicking the Resolution dropdown in Master Settings, not after you've started editing.
  • DaVinci Resolve offers preset ratios like 16:9, 4:3, 1:1, and 9:16, or you can select Custom to enter any ratio you need.
  • Changing aspect ratio after you've edited means manually adjusting every clip in your timeline, so planning ahead saves hours of work.
  • If you do change the ratio later, you can scale and reposition clips using the Inspector panel on the right side of the Edit page.

Change aspect ratio on an existing project

If you've already started editing and need to change the aspect ratio, go to the Edit page (the tab at the top of the screen). In the top menu, click Project Settings. A window opens showing your current Resolution setting. Click the dropdown, choose a new ratio, and click Save.

The timeline itself will now show the new dimensions, but your clips won't automatically resize or reframe to fit. You'll see black bars or empty space around your footage. To fix each clip, click it in the timeline to select it. On the right side of the screen, you'll see the Inspector panel. Under the Transform section, you can adjust Scale to make the clip larger or smaller, and use Offset X and Offset Y to move it around until it fills the frame the way you want.

If you have many clips, this becomes tedious. A faster approach is to select all clips at once (click the first one, hold Shift, and click the last one), then adjust them together in the Inspector. They'll all scale and move the same way, though you may still need to fine-tune individual clips afterward.

Understand what aspect ratio actually does

Aspect ratio is the width-to-height proportion of your video frame. A 16:9 frame is wider and shorter — it's what you see on most modern TVs and YouTube videos. A 4:3 frame is more square-shaped, common in older broadcasts and some documentary work. A 1:1 frame is perfectly square, popular on Instagram and TikTok. A 9:16 frame is taller than it is wide, designed for vertical phone video.

When you set a project ratio in DaVinci Resolve, you're telling the software what shape your final video should be. If your source footage doesn't match that shape, DaVinci Resolve won't crop it automatically — it will either letterbox it (add black bars on the sides) or pillarbox it (add black bars on top and bottom). You then decide whether to scale the footage to fill the frame, keep the black bars, or crop the footage to remove them.

This is why setting the ratio before you import footage matters. If you know you're making a vertical video for TikTok, set it to 9:16 from the start. Your timeline will be shaped that way, and you'll frame your shots with that proportion in mind as you edit. If you change it halfway through, you're essentially redesigning your entire edit.

Match your aspect ratio to where the video will play

Before you choose an aspect ratio, think about where your finished video will be watched. YouTube and most streaming platforms accept many ratios, but they display them differently. A 16:9 video fills the screen on a desktop or TV. A 9:16 video fills a phone screen held vertically. A 1:1 video works well on Instagram feed posts or as a square thumbnail.

If you're not sure where your video will end up, 16:9 is the safest choice — it's the standard for most platforms and devices. But if you know it's going to TikTok or Instagram Reels, start with 9:16. If it's for a film festival or cinema, consider 2.39:1 or 21:9. Choosing the right ratio at the start means less rework later.

You can also export the same project in multiple ratios if you need to. Finish editing in one ratio, then duplicate the project, change the ratio in the duplicate, adjust the clips to fit, and export. This way you have versions ready for different platforms without starting from scratch.

Use the Fusion page to adjust clips without changing the project ratio

If you want to keep your project in one ratio but adjust individual clips to a different shape, the Fusion page gives you more control than the Inspector. Click the Fusion tab at the top of DaVinci Resolve. Select a clip in the timeline. You'll see a node-based interface on the left side. Right-click in the empty space and select Add Tool, then choose Transform.

The Transform tool lets you scale, rotate, and reposition clips with more precision than the Inspector. You can also add effects like blur or color correction to individual clips without affecting the whole project. This is useful if you're mixing footage from different sources or aspect ratios in a single edit.

The Fusion page has a steeper learning curve than the Edit page, so use it only if you need frame-by-frame control. For most aspect ratio adjustments, the Inspector on the Edit page is faster and simpler.

Export your video in the correct aspect ratio

Once you've finished editing, you need to export your video in the aspect ratio you set. Go to the Deliver page (the tab at the top). On the left side, you'll see Render Settings. Under Video, check the Resolution field. It should match the ratio you chose for your project. If it doesn't, click the dropdown and select the correct one.

Below that, you'll see Frame Rate (usually 24, 25, or 30 frames per second) and Codec (the format your video will be compressed into, like H.264 or ProRes). These don't affect aspect ratio, but they do affect file size and quality. For YouTube or social media, H.264 is standard. For archival or professional work, ProRes is better.

Choose a filename and location, then click Add to Render Queue. DaVinci Resolve will process your video and save it with the aspect ratio you set. Check the exported file on your phone or computer to make sure it looks right before you upload it anywhere.

Frequently Asked Questions

Can I change aspect ratio for just one clip in my timeline?

Yes. Select the clip, open the Inspector panel on the right, and adjust the Scale and Offset values. The rest of your timeline stays in the project ratio. This is useful if you're mixing clips from different cameras or sources.

What happens if my source footage is a different aspect ratio than my project?

DaVinci Resolve will letterbox or pillarbox the clip — add black bars to fit it into your project shape. You can then scale the clip larger to fill the frame (which crops the edges) or leave the black bars. There's no single right answer; it depends on your footage and creative choice.

Can I export the same project in multiple aspect ratios?

Yes. Finish editing in one ratio, then go to the Deliver page and change the Resolution dropdown before you export. You can export as many times as you want with different settings. Alternatively, duplicate your project, change the project ratio, adjust clips, and export separately.

Is there a way to automatically fit all my clips to a new aspect ratio?

Not automatically, but you can select all clips at once (Ctrl+A or Cmd+A), then adjust them together in the Inspector. They'll scale and move uniformly, though you may still need to fine-tune individual clips afterward.

What aspect ratio should I use for a video I'm uploading to YouTube?

16:9 is the standard and fills most screens. YouTube accepts other ratios and will add black bars if needed, but 16:9 looks best without letterboxing. If your video is vertical (shot on a phone), use 9:16 instead.