Free Aspect Ratio Calculator Online
Calculate and maintain aspect ratios for images, videos, and screens. Scale dimensions proportionally to avoid distortion.
What is Aspect Ratio?
Aspect ratio is the proportional relationship between width and height. It's expressed as two numbers separated by a colon (e.g., 16:9). Maintaining aspect ratio is crucial when resizing images or videos to prevent stretching or squashing.
Features of Our Aspect Ratio Calculator
- Calculate ratio - Find the ratio from any dimensions
- Common presets - 16:9, 4:3, 1:1, 9:16, 21:9
- Scale calculator - Get new dimensions while keeping ratio
- Decimal ratio - See the exact decimal value
- GCD calculation - Reduces to simplest form
- Mobile friendly - Works on any device
Common Aspect Ratios
| Ratio | Decimal | Common Uses |
|---|---|---|
| 16:9 | 1.778 | HD video, YouTube, modern TVs |
| 4:3 | 1.333 | Old TVs, iPad, classic photos |
| 1:1 | 1.000 | Instagram posts, profile pictures |
| 9:16 | 0.563 | Stories, TikTok, Reels, vertical video |
| 21:9 | 2.333 | Ultrawide monitors, cinema |
| 3:2 | 1.500 | DSLR photos, 35mm film |
| 2:3 | 0.667 | Portrait photos, Pinterest |
| 4:5 | 0.800 | Instagram portrait |
How to Use the Aspect Ratio Calculator
Find the Aspect Ratio
- Enter the width and height
- View the simplified ratio (e.g., 16:9)
- See the decimal equivalent
Scale While Keeping Ratio
- Enter original dimensions
- Enter either new width OR new height
- Get the other dimension calculated automatically
How Aspect Ratios Work
The aspect ratio W:H means for every W units of width, there are H units of height. When scaling:
- New Width = Original Width × Scale Factor
- New Height = Original Height × Scale Factor
Both dimensions must use the same scale factor to maintain proportion.
FAQs About Aspect Ratios
What's the most common aspect ratio for video?
16:9 is the standard for HD and 4K video, YouTube, Netflix, and modern television.
What aspect ratio should I use for social media?
- Instagram Feed: 1:1 (square) or 4:5 (portrait)
- Instagram Stories/Reels: 9:16
- YouTube: 16:9
- TikTok: 9:16
- Twitter: 16:9 or 2:1
How do I calculate aspect ratio manually?
Divide both width and height by their Greatest Common Divisor (GCD). For example, 1920×1080: GCD is 120, so 1920/120 = 16 and 1080/120 = 9, giving 16:9.
What happens if I don't maintain aspect ratio?
The image or video will appear stretched or squashed, distorting the original content.
Use Cases
- Image resizing - Scale photos without distortion
- Video editing - Match format requirements
- Web design - Responsive image containers
- Print design - Ensure correct proportions
- Screen resolution - Calculate display dimensions
Resolution Presets
| Name | Resolution | Aspect Ratio |
|---|---|---|
| Full HD | 1920×1080 | 16:9 |
| 4K UHD | 3840×2160 | 16:9 |
| 1080p Vertical | 1080×1920 | 9:16 |
| Instagram Square | 1080×1080 | 1:1 |
| Instagram Portrait | 1080×1350 | 4:5 |
Why Use Our Aspect Ratio Calculator?
- Free to use - No registration needed
- Instant results - Real-time calculation
- Preset ratios - Common formats included
- Bidirectional scaling - Enter width or height
- Simple interface - Easy to understand