Calculate image & video dimensions for any aspect ratio
How would a 16:9 image fit in a different ratio?
| Ratio | Name | Common Use | Example Resolution |
|---|---|---|---|
| 16:9 | Widescreen | HD video, YouTube, TV | 1920×1080 |
| 4:3 | Standard | Classic TV, iPad, print | 1024×768 |
| 21:9 | Ultrawide | Cinema, ultrawide monitors | 2560×1080 |
| 1:1 | Square | Instagram, profile photos | 1080×1080 |
| 3:2 | DSLR | Photography, prints | 3000×2000 |
| 9:16 | Vertical | TikTok, YouTube Shorts | 1080×1920 |
| 2:1 | Univisium | Netflix, cinematic | 2048×1024 |
| 5:4 | Large format prints | 1280×1024 | |
| 32:9 | Super Ultrawide | Dual-wide monitors | 5120×1440 |
An aspect ratio is the proportional relationship between the width and height of an image, video, or screen. It's expressed as two numbers separated by a colon (e.g., 16:9), meaning the width is 16 units for every 9 units of height.
Divide the width by the height, then find the simplest whole-number ratio. For example, 1920×1080: 1920÷1080 = 1.778, and 16÷9 = 1.778, so the aspect ratio is 16:9. Our calculator does this automatically — just enter any dimension.
16:9 is the standard widescreen ratio used for HD TV, YouTube, and most modern displays. 4:3 is the classic TV and print ratio — squarer. 16:9 is wider (1.78:1), while 4:3 is taller relative to its width (1.33:1).
YouTube recommends 16:9 (widescreen) for standard videos, which is 1920×1080 or 3840×2160 pixels. For Shorts, use 9:16 (vertical), which is 1080×1920 pixels.
To resize without distortion, you must maintain the aspect ratio. Lock one dimension and calculate the other. For example, if you have a 16:9 image and need it 800px wide, the height is 800 × (9÷16) = 450px. Our calculator handles this automatically.
21:9 (ultrawide) is used for cinematic content, ultrawide monitors, and filmmaking. It matches the 2.35:1 or 2.39:1 anamorphic scope used in movies. Common resolutions include 2560×1080 and 3440×1440.
Converting between ratios requires either cropping (removing pixels) or padding (adding letterbox bars). For example, converting 4:3 to 16:9 means cropping top and bottom, or adding black bars on the sides (pillarboxing). Our tool calculates the resulting dimensions for both approaches.
Common ratios: 16:9 (1920×1080, 3840×2160 — HD/4K), 4:3 (1024×768, 2048×1536 — classic/print), 21:9 (2560×1080 — ultrawide), 1:1 (1080×1080 — Instagram square), 3:2 (3000×2000 — DSLR), 9:16 (1080×1920 — vertical video/Shorts).
An image looks stretched when it's displayed at a different aspect ratio than its original. For example, showing a 4:3 photo on a 16:9 screen without letterboxing stretches it wider. Always maintain the original aspect ratio when resizing, or crop intentionally.
PPI (pixels per inch) measures display density. Higher PPI means sharper text and images. A 27-inch 4K monitor has ~163 PPI, while a 27-inch 1080p monitor has ~82 PPI. Our calculator shows PPI for common screen sizes.