Aspect Ratio Calculator
Easily calculate, convert, or simplify any aspect ratio. Enter your ratios or pixel dimensions to get the exact proportion for any resolution. Ideal for video creators, photographers, designers, and developers.
Want to explore all common video, photo, and cinema aspect ratios? Check the Aspect Ratio Chart .
Need the right dimensions for Instagram, YouTube, or TikTok? See the Social Media Image Sizes guide .
⭐ What Is an Aspect Ratio?
The aspect ratio describes the proportional relationship between the width and height of an image, video, or screen.
It’s usually written as two numbers separated by a colon, for example:
- 16 : 9
- 4 : 3
- 21 : 9
An aspect ratio does not represent a specific size; it represents a shape.
Any resolution that matches the same width-to-height proportion uses the same aspect ratio. For example, 1920 × 1080 and 1280 × 720 are both 16 : 9.
⭐ How Aspect Ratios Are Calculated
An aspect ratio is calculated by comparing width and height and then simplifying the pair to its smallest whole-number form. The most common method is dividing both values by their greatest common divisor (GCD).
Example: 1920 × 1080
- Find the GCD of 1920 and 1080 (GCD = 120).
- Divide both numbers by 120: 1920 ÷ 120 = 16, 1080 ÷ 120 = 9.
- Result: 16 : 9.
This is why different resolutions can share the same aspect ratio: for example, 1280 × 720 also simplifies to 16 : 9.
⭐ How to Use This Aspect Ratio Calculator
You can use this tool in two main ways:
1. Enter a Width Ratio and Height Ratio
For example:
- Width ratio: 16
- Height ratio: 9
The calculator will simplify your input and display the normalized aspect ratio.
2. Enter a Width and Height in Pixels
For example:
- Width: 1920px
- Height: 1080px
The calculator will detect the underlying ratio and show you the closest matching aspect ratio (with optional rounding).
This is especially useful for UI designers, filmmakers, photographers, and developers who want to confirm the correct ratio for their layouts, videos, or images.