Aspect Ratio Calculator
Find the simplified ratio for any resolution, or scale dimensions proportionally. Perfect for video, images, and screen design.
Select a common preset or enter a custom ratio, then enter one dimension to calculate the other.
| Ratio | Decimal | Common Uses | Examples |
|---|---|---|---|
| 16:9 | 1.778 | Video Display | 1080p, 4K, YouTube |
| 4:3 | 1.333 | Legacy Photo | Old TV, iPad |
| 21:9 | 2.333 | Ultrawide Cinema | Ultrawide monitors |
| 1:1 | 1.000 | Social | Instagram, Profile pics |
| 9:16 | 0.563 | Mobile Stories | TikTok, Reels, Stories |
| 3:2 | 1.500 | Photo Print | DSLR, 35mm film |
| 5:4 | 1.250 | Print Display | 5×4 prints, old monitors |
| 2:1 | 2.000 | Cinema | Netflix originals |
| 2:3 | 0.667 | Portrait Print | Portrait photography |
| 4:5 | 0.800 | Social | Instagram portrait posts |
| 1.85:1 | 1.850 | Cinema | US theatrical standard |
| 2.39:1 | 2.390 | Cinema | Anamorphic widescreen |
What is an Aspect Ratio?
An aspect ratio describes the proportional relationship between an image or screen's width and height. It's expressed as two numbers separated by a colon, like 16:9 — meaning for every 16 units of width, there are 9 units of height.
Aspect ratios are reduced to their simplest form using the Greatest Common Divisor (GCD). For example, 1920×1080 simplifies to 16:9 because both numbers are divisible by 120.
When scaling, one dimension determines the other to preserve the ratio. Always calculate new dimensions this way to avoid distortion in images and video.