Glossary/A
Aspect ratio
What it meansThe relationship between an ad’s width and its height, written as two numbers (9:16, 4:5, 1:1) or as one, width divided by height. Two sizes with the same aspect ratio are the same shape at different resolutions and take the same layout; two sizes with different ratios need different layouts, however close their pixel counts.
- Also called
- Ratio, shape
- Applies to
- Every image and video size
- Set by
- Each placement’s specs
The common ones
| Ratio | Example size | Width ÷ height | Shape |
|---|---|---|---|
| 9:161 | 1440×2560 | 0.56 | Tall: Stories, Reels |
| 4:52 | 1440×1800 | 0.80 | Portrait: Feed |
| 1:1 | 1080×1080 | 1.00 | Square |
| 300×2503 | 300×250 | 1.20 | Near square: display |
| 728×903 | 728×90 | 8.09 | Banner: display |
Display sizes are listed in pixels rather than as ratios; the division gives their shape.3
A worked example
Example numbers. Is 1440×2560 the same shape as 1080×1920? Divide each: 1440 ÷ 2560 = 0.5625 and 1080 ÷ 1920 = 0.5625. Same number, same shape: a layout made for one fits the other without moving anything. Is 1440×1800 the same shape as 1080×1080? 0.80 against 1.00: no, and a square layout placed on a 4:5 frame leaves a band empty at the bottom.
What it means in practice
Group the sizes in a media plan by ratio before making any of them: each ratio is one layout, however many sizes and placements share it. The smaller the width-to-height number, the taller the size, so a 300×600 half page (0.50) belongs with the 9:16 Story layout (0.56), not with the banners.
A change of ratio is a change of layout, never a crop. Cropping a 4:5 master to 9:16 keeps 70% of its width, and the edges it loses are usually where the logo and price sit.
Common mistakes
- Treating close ratios as the same.4:5 and 9:16 look close; the same layout does not fit both.
- Grouping by platform instead of ratio.A half-page display ad shares a layout with a Story, not with a leaderboard.
- Making every size from the square.Every shape that is not square then needs a crop or a gap.
Sources
- Image ad specs on Instagram Stories, Meta Ads Guide. 9:16, 1440×2560, and the 14% / 35% / 6% safe zone.Checked 25 Oct 2026
- Image ad specs, Facebook Feed, Meta Ads Guide. 4:5, 1440×1800.Checked 25 Oct 2026
- About common sizes for responsive display ads, Google Ads Help. Common display sizes on computers and mobile.Checked 25 Oct 2026