Aspect ratio calculator and resizer
Enter the width and height to get the simplified ratio. 1920 × 1080 is 16:9; scaled down to 1280 px wide, the image is 720 px tall.
- Checked on thousands of cases
- Updated November 6, 2026
Common ratios
Aspect ratio
Decimal ratio : 1.7778
Quick challenge
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Test yourself: every answer is computed by the tool, and the wrong choices are the most common traps.
How it works
Formula: New height = new width × height ÷ width
The aspect ratio is width ÷ height in its simplest form: both sides are divided by their greatest common divisor. 1920 and 1080 are both divisible by 120, which gives 16:9. To resize without distortion, keep the same ratio: new height = new width × height ÷ width. Some resolutions have no exact ratio: 1366 × 768 is 683:384, very close to 16:9.
Common ratios and matching heights
| Ratio | Decimal ratio | Height at 1,080 px wide | Height at 1,280 px wide | Height at 1,920 px wide | Height at 3,840 px wide |
|---|---|---|---|---|---|
| 1:1 | 1 | 1,080 px | 1,280 px | 1,920 px | 3,840 px |
| 4:3 | 1.3333 | 810 px | 960 px | 1,440 px | 2,880 px |
| 3:2 | 1.5 | 720 px | 853.33 px | 1,280 px | 2,560 px |
| 16:10 | 1.6 | 675 px | 800 px | 1,200 px | 2,400 px |
| 16:9 | 1.7778 | 607.5 px | 720 px | 1,080 px | 2,160 px |
| 9:16 | 0.5625 | 1,920 px | 2,275.56 px | 3,413.33 px | 6,826.67 px |
| 4:5 | 0.8 | 1,350 px | 1,600 px | 2,400 px | 4,800 px |
| 2:1 | 2 | 540 px | 640 px | 960 px | 1,920 px |
Frequently asked questions
Which sizes are 16:9?
Any size whose width divided by its height is 16 ÷ 9, about 1.78: 1280 × 720, 1920 × 1080 or 3840 × 2160, for example.
How do I resize an image without stretching it?
Keep the same ratio: multiply the new width by the original height, then divide by the original width. A 4000 × 3000 photo scaled to 1200 px wide is 900 px tall.
What does 9:16 mean?
It is 16:9 turned upright: 9 wide for 16 tall, for example 1080 × 1920 pixels.