How to Calculate Aspect Ratio
Aspect ratio is simply the relationship between how wide something is and how tall it is. There are two common ways to express it once you know the width and height.
Method 1 — as a decimal
Divide the width by the height. Whatever number you get is the ratio of width to a height of 1, written as "that number : 1". For a 1920 x 1080 screen, 1920 / 1080 = 1.777..., which rounds to 1.78:1.
Method 2 — as whole numbers
Find the greatest common factor (GCF) of the width and height, then divide both by it. For 1920 x 1080, the GCF is 120: 1920 / 120 = 16, and 1080 / 120 = 9. That gives the familiar whole-number ratio 16:9 — the same shape as 1.78:1, just written differently.
Once you have a ratio, you can go the other way too: given a target width, multiply it by (height / width) of the ratio to get the matching height, or vice versa. That's exactly what the "Find Width" and "Find Height" modes above do for you automatically.
Why Aspect Ratio Matters
Screens, images and video frames all come in different shapes, and content has to be sized to fit each one correctly. Resize an image without preserving its ratio and it will look stretched, squashed, or you'll lose part of the picture to cropping.
It also matters for publishing: platforms like YouTube, TikTok, Instagram, LinkedIn and Snapchat each have preferred or required ratios for video and image posts. Get it wrong and your content may be cropped, letterboxed, or shrunk down by the platform.
The same logic applies to advertising creative — banner ads, tower ads, and square units all have their own expected ratios, so checking the target platform's spec sheet before you design is worth the two minutes it takes.
Standard Aspect Ratios
Common ratios used across displays, photography and video, sorted by width/height value. Click any row's ratio into the calculator above to explore it further.
| Ratio (W:H) | Width | Height | W/H | Typical use |
|---|---|---|---|---|
| 9:16 | 9 | 16 | 0.563 | Vertical / mobile video (TikTok, Reels, Shorts) |
| 3:4 | 3 | 4 | 0.75 | Portrait photos, tablet portrait |
| 1:1 | 1 | 1 | 1 | Square posts, profile avatars |
| 5:4 | 5 | 4 | 1.25 | Older monitors, some print formats |
| 4:3 | 4 | 3 | 1.333 | Classic TV and CRT monitors |
| 3:2 | 3 | 2 | 1.5 | 35mm and DSLR photography |
| 14:9 | 14 | 9 | 1.556 | Broadcast compromise ratio |
| 16:10 | 16 | 10 | 1.6 | Widescreen laptop displays |
| 16:9 | 16 | 9 | 1.778 | HD/4K video, modern TVs and monitors |
| 1.85:1 | 1.85 | 1 | 1.85 | Widescreen cinema |
| 17:9 | 17 | 9 | 1.889 | Digital cinema (DCI) |
| 2:1 | 2 | 1 | 2 | Univisium / modern streaming films |
| 21:9 | 21 | 9 | 2.333 | Ultrawide monitors |
| 2.35:1 | 2.35 | 1 | 2.35 | Anamorphic widescreen cinema |
| 2.39:1 | 2.39 | 1 | 2.39 | Modern anamorphic cinema |
| 32:9 | 32 | 9 | 3.556 | Super-ultrawide monitors |