Aspect Ratio Calculator
Calculate width, height or aspect ratio for any image or video dimensions. Lock ratio, scale up/down and get common ratio presets. Free, browser-based.
💻 Developer Tools
Free
Browser-based
Common Ratios
16 : 9
Aspect Ratio
1.778
Decimal
2.07 MP
Megapixels
Preview
Scale to new width / height
What is an Aspect Ratio?
An aspect ratio describes the proportional relationship between width and height, written as W:H. A 1920×1080 image has a 16:9 aspect ratio — the same as a 1280×720 image. Aspect ratios are essential for video production, responsive design, image cropping and screen layouts.
Common Aspect Ratios
| Ratio | Example resolution | Common use |
|---|---|---|
| 16 : 9 | 1920×1080 | HD video, monitors, YouTube |
| 4 : 3 | 1024×768 | Legacy monitors, presentations |
| 1 : 1 | 1080×1080 | Instagram square posts |
| 9 : 16 | 1080×1920 | Mobile, TikTok, Stories |
| 21 : 9 | 2560×1080 | Ultrawide monitors, cinema |
| 3 : 2 | 1920×1280 | DSLRs, photography |
Tips
When scaling images, always calculate the missing dimension from the known one to avoid distortion. Use the scale fields below the main calculator — enter just the new width or height and the matching dimension is calculated for you automatically.