Aspect Ratio Calculator
What is Aspect Ratio?
Aspect Ratio is the relationship between the width and the height of an image, video, or screen. It is usually written as two numbers separated by a colon, like 16:9.
Important Note: Aspect ratio describes the shape, not the size.
- A small phone screen (1920x1080) has a 16:9 ratio.
- A giant stadium billboard (19200x10800) also has a 16:9 ratio.
Common Ratios Cheat Sheet
Different platforms require different shapes. If you upload the wrong shape, your content will get cropped or have black bars added.
| Ratio | Use Case | Example Resolution |
|---|---|---|
| 1:1 | Square (Instagram Grid) | 1080 x 1080 |
| 16:9 | Widescreen (YouTube, TV) | 1920 x 1080 (HD) |
| 9:16 | Vertical (TikTok, Reels, Shorts) | 1080 x 1920 |
| 4:3 | Old TV / Standard Photo | 1024 x 768 |
| 4:5 | Instagram Portrait (Best Visibility) | 1080 x 1350 |
| 21:9 | Ultrawide Monitor / Cinema | 2560 x 1080 |
Instagram allows 1:1 (Square) or 4:5 (Tall) for posts. Always choose 4:5. Why? It takes up more vertical space on the user's phone screen, which statistically captures more attention and engagement than a small square image.
How to Calculate it Manually
To find the aspect ratio of any image, you need to find the Greatest Common Divisor (GCD) of the width and height.
Example: An image is 800 wide by 600 high.
- Divide both by 100: 8 and 6.
- Divide both by 2: 4 and 3.
- Result: 4:3 Ratio.
Resizing Without Distortion
When you resize an image, you must "Lock the Aspect Ratio." This means if you change the width, the height must change mathematically to match.
If you have a 1920 x 1080 image and you want to shrink the width to 500 px:
- Formula: New Height = (Original Height / Original Width) × New Width
- Math: (1080 / 1920) × 500 = 281.25 px.
Our calculator does this automatically, ensuring your images never look "squashed" or "stretched."