Resize dimensions while keeping the ratio locked
Aspect ratio is the proportional relationship between width and height, reduced to its simplest form using the greatest common divisor. A 1920×1080 image and a 1280×720 image both have a 16:9 ratio — the same shape, just different sizes.
| Ratio | Common use | Typical dimensions |
|---|---|---|
| 16:9 | HD/4K video, monitors, TV, YouTube | 1920×1080, 3840×2160 |
| 4:3 | Standard definition TV, older monitors | 1024×768, 800×600 |
| 1:1 | Instagram square, profile photos | 1080×1080 |
| 4:5 | Instagram portrait feed posts | 1080×1350 |
| 9:16 | Stories, Reels, TikTok, vertical video | 1080×1920 |
| 3:2 | DSLR camera sensors, 35mm film | 6000×4000, 3000×2000 |
| 2:1 | Panoramic photos, cinematic ultra-wide | 2048×1024 |
| 3:1 | Twitter/X header banner | 1500×500 |
| √2:1 | A-series paper (A4, A3, A5) | 297×210 mm (A4) |
| 17:22 | US Letter paper | 8.5×11 inches |
Every platform has different image dimension requirements. Using the correct size prevents automatic cropping, black bars, and blurry upscaling. Use the presets above to load any of these directly into the calculator.
| Platform & format | Dimensions | Ratio |
|---|---|---|
| YouTube thumbnail | 1280 × 720 px | 16:9 |
| Instagram square | 1080 × 1080 px | 1:1 |
| Instagram portrait | 1080 × 1350 px | 4:5 |
| Instagram / TikTok Story | 1080 × 1920 px | 9:16 |
| Twitter / X post image | 1600 × 900 px | 16:9 |
| Twitter / X header | 1500 × 500 px | 3:1 |
| Facebook cover photo | 820 × 312 px | ~2.63:1 |
| LinkedIn cover photo | 1584 × 396 px | 4:1 |
| Open Graph (link preview) | 1200 × 630 px | ~1.91:1 |
Enter your original width and height and the simplified ratio is calculated instantly using the greatest common divisor algorithm. Enter a new width or height and the other dimension is calculated automatically to preserve the exact ratio. Use the presets for common video, social media, and print formats. The proportional preview box updates in real time to show the visual shape of your ratio.