Aspect Ratio for Video: 16:9, 9:16 & Best Video Sizes

What aspect ratio should a video be?

A video’s aspect ratio should match wherever it’ll be watched, and most of the time that means 16:9 for landscape or 9:16 for vertical. There’s no single right answer, since a phone screen and a TV want opposite shapes from each other.

Landscape 16:9 is the default for YouTube, TVs, and nearly every desktop player, so it’s the safe pick when you’re unsure. Vertical 9:16 owns the phone, which is where short clips live now. About 75% of web traffic happens on mobile, so vertical formats keep growing fast. If you’re filming for Reels, TikTok, or Shorts, you’ll want 9:16. If it’s a tutorial or a longer YouTube upload, stick with 16:9. The video aspect ratio you choose decides whether viewers see black bars, an awkward crop, or a clean edge-to-edge frame. Once you’ve picked the platform, the ratio almost picks itself.

What are the standard video aspect ratios?

The standard video aspect ratios boil down to a short list that platforms have settled on over the years. You’ll meet six of them again and again, and each one pairs with a go-to resolution. Here’s a reference you can keep handy when you’re setting up an export.

Platform / use	Aspect ratio	Resolution
YouTube, landscape	16:9	1920x1080
YouTube Shorts, TikTok, Reels	9:16	1080x1920
Instagram feed	1:1	1080x1080
Instagram portrait	4:5	1080x1350
Cinema, film	2.39:1 or 21:9	2560x1080
TV broadcast	16:9	1920x1080

A couple of things stand out here. The 16:9 standard covers roughly 90% of long-form video online, so it’s doing the heavy lifting. The 9:16 vertical group has exploded since short clips took over, and all three big apps share the exact same 1080x1920 frame. That’s handy, because one vertical export can feed TikTok, Reels, and Shorts without any reframing. For the math behind any of these pairs, our aspect ratio calculator reduces the numbers for you.

What is 16:9 and why is it the video standard?

16:9 is a widescreen shape that’s 16 units wide for every 9 units tall, and it’s the default for HDTV, YouTube, and almost every modern video player. Its decimal form is 1.78:1, which is why you’ll sometimes see that number in export menus.

The reason 16:9 won out is simple compatibility. When HDTV arrived, broadcasters and screen makers agreed on it, so monitors, TVs, laptops, and streaming sites all built around the same frame. That means a 16:9 video fills the screen with no letterboxing on the vast majority of devices people own. The standard resolution is 1920x1080, often called Full HD or 1080p, though 1280x720 and 3840x2160 are also 16:9 at lower and higher detail. You don’t have to think about it much, which is exactly the point. If you’re not making something for a phone, 16:9 is almost always the right call, and it’s what your viewers expect. For the quick 16:9 sums, the 16:9 calculator handles the matching side.

What is 9:16 vertical video for?

9:16 vertical video is built for phones held upright, so the frame is tall instead of wide. It’s literally 16:9 flipped on its side, which is why it feels so dramatically vertical compared to a normal clip.

This shape powers the apps people scroll one-handed: TikTok, Instagram Reels, Facebook Stories, and YouTube Shorts. The standard vertical video size is 1080x1920, and that single export works across every one of them. Because phones are held upright most of the time, vertical video fills the whole screen without forcing viewers to rotate. That edge-to-edge fit is a big reason short vertical clips hold attention better than a small landscape window stuck in the middle. When you’re filming, lock your camera or phone to portrait and frame for the center third, since app interfaces cover the top and bottom edges. If you’ve shot landscape by mistake, you’ll either crop hard or live with bars, so it’s worth getting the orientation right before you record. You can double-check any clip’s shape with the aspect ratio calculator.

What about square (1:1) and 4:5 video?

Square 1:1 and portrait 4:5 are the social-feed shapes that sit between full landscape and full vertical. They don’t fill a whole phone screen like 9:16 does, but they grab more feed space than a wide clip, which helps them stand out.

Square 1:1 is exactly as wide as it’s tall, with 1080x1080 the common size. It looks balanced in a grid and never favors width or height, so it’s a safe, tidy choice for feed posts. Portrait 4:5 is a touch taller at 1080x1350, and that extra height is the whole point. On Instagram’s feed, a 4:5 post takes up more vertical room than a square, so it pushes competing posts down and earns a longer look. Here’s the trade-off: 4:5 isn’t as tall as 9:16, so it won’t dominate the screen the way a Reel does, but it also won’t get cropped in the feed the way a vertical video might. If you’re posting to a feed rather than to Stories or Reels, 4:5 usually gives you the best balance of reach and fit. Either way, exporting at 1080 pixels on the short side keeps things crisp.

How do you keep the right aspect ratio when exporting video?

You keep the right aspect ratio by setting your project or sequence to that ratio before you export, so every frame matches the target from the start. Fixing it at the export stage is harder, because you’re cropping or padding footage that was framed for a different shape.

Start in your editing software’s sequence settings. Pick the platform’s ratio there, like 1920x1080 for 16:9 or 1080x1920 for 9:16, and your timeline previews exactly what viewers will see. That way you’ll spot a bad crop while you’re still editing, not after upload. Avoid mixing ratios mid-project, since dropping vertical clips into a landscape sequence leaves pillarbox bars on the sides, and the reverse leaves letterbox bars top and bottom. If you do need a new size, the math is short: new height equals width divided by the ratio value, so a 1920-wide 16:9 frame works out to 1920 / 1.78, which rounds to 1080. Going vertical, you’d flip it. Match the platform first, set the sequence to that shape, then export at the highest resolution the file budget allows. For converting physical print sizes into pixels, our inches to pixels tool bridges the gap.

How do you check a video’s aspect ratio?

To check a video’s aspect ratio, divide its pixel width by its height and simplify the pair down to whole numbers. A 1920x1080 file divides to 1.78, which reduces to 16:9, while 1080x1920 gives the vertical 9:16.

You’ll find the pixel dimensions in your file’s properties, in the editor’s clip info, or in any media player’s stats panel. Once you’ve got the two numbers, reducing them is the same trick used for photos: divide both sides by their greatest common divisor. For 1920 and 1080 that divisor is 120, which lands you on 16:9. If the numbers don’t reduce to a familiar pair, the decimal still tells you the shape, so 1.78 means widescreen and 0.56 means tall vertical. Knowing how to read it saves you from uploading a clip that gets cropped or boxed. If you’d rather skip the arithmetic, paste your dimensions into the aspect ratio calculator and it returns the simplified ratio instantly. For more background on how shape and pixels relate, our guides on common aspect ratios and what is aspect ratio walk through the basics. And when you’re sizing a clickable preview, the YouTube thumbnail size reference keeps that image sharp too.