What Is an Aspect Ratio?

Aspect ratio is the relationship between a video frame's width and its height, written as width:height. It defines the frame's shape, independent of resolution.

The ratios that matter now

• 16:9 — horizontal, standard for YouTube and desktop viewing.
• 9:16 — vertical, for Shorts, TikTok and Reels.
• 1:1 — square, for feed posts.
• 4:5 — portrait feed, taller than square without being full vertical.

Ratio versus resolution

1920x1080 and 1280x720 are both 16:9. Ratio is shape; resolution is pixel count. Editsfield AI combines the two: pick the aspect ratio, then pick 720p, 1080p or 4K.

Choose the ratio before you shoot

Reframing horizontal footage into a vertical frame loses the sides. If a vertical cut is planned, keep the subject centred while filming.