Aspect Ratio Calculator
Calculate aspect ratios from dimensions, find missing width or height while maintaining ratio, with visual preview and common presets.
Aspect Ratio
16:9
Width
1920 px
Height
1080 px
Decimal Ratio
1.78
VISUAL PREVIEW
Common Aspect Ratios
| Ratio | Decimal | Usage |
|---|---|---|
| 16:9 | 1.78 | HD video, widescreen displays, YouTube |
| 4:3 | 1.33 | Classic TV, older displays, presentations |
| 1:1 | 1.00 | Instagram posts, square images |
| 21:9 | 2.33 | Ultrawide monitors, cinematic video |
| 9:16 | 0.56 | Vertical video, TikTok, Instagram Stories |
| 1.618:1 | 1.62 | Golden ratio, photography, design |
| 3:2 | 1.50 | 35mm film, DSLR cameras |
| 2.39:1 | 2.39 | Anamorphic widescreen, cinema |
How to Use the Aspect Ratio Calculator
Choose the appropriate tab for your calculation need: find the aspect ratio from dimensions, calculate missing width, or calculate missing height. Enter your values and see instant results with visual preview.
- Select the appropriate tab: Find Ratio, Calc Width, or Calc Height
- Enter your known dimensions (width and/or height)
- Use preset buttons to apply common aspect ratios (16:9, 4:3, etc.)
- Select your preferred unit (pixels, inches, centimeters, etc.)
- View results with visual preview showing the proportions
Aspect Ratio Formulas
Find Aspect Ratio:
Ratio = Width : Height (simplified to lowest terms)
Decimal Ratio = Width / Height
Calculate Width:
Width = Height × (Ratio Width / Ratio Height)
Calculate Height:
Height = Width / (Ratio Width / Ratio Height)
For example, with 16:9 ratio and height of 1080px: Width = 1080 × (16 / 9) = 1920px.
Frequently Asked Questions
Aspect ratio is the proportional relationship between width and height of an image, screen, or video. It's expressed as two numbers separated by a colon (e.g., 16:9), where the first number represents width and the second represents height.
16:9 (widescreen) became the standard for HD television, computer monitors, and online video platforms like YouTube. It provides a good balance between width and height, matching the natural field of human vision better than older 4:3 format.
To maintain aspect ratio when resizing, you must scale both width and height proportionally. If you know the new width, divide it by the original width to get the scale factor, then multiply the original height by this factor. This calculator automates this process.
The golden ratio (1.618:1 or approximately 16:10) is a mathematical ratio found in nature and art. It's considered aesthetically pleasing and is often used in photography, design, and architecture. It's slightly wider than 16:9.
It depends on the platform: Instagram posts (1:1 or 4:5), Instagram Stories/Reels (9:16), YouTube (16:9), TikTok (9:16), Facebook posts (1.91:1), Twitter posts (16:9 or 2:1). Using the correct ratio ensures your content displays properly without cropping.
Using the wrong aspect ratio can result in black bars (letterboxing or pillarboxing), stretching/distortion, or unwanted cropping. This is especially problematic for video content and images on social media where parts of your content may be cut off.
Converting between aspect ratios requires either cropping (removing parts of the image) or adding padding (black bars). Choose the dimension you want to keep (usually width), calculate the new height for your target ratio, then crop or pad accordingly. This may result in content loss.