Aspect Ratio Calculator

Calculate, scale, and convert image aspect ratios for any use case

Calculate Aspect Ratio from Dimensions

Enter your image or video dimensions to find the aspect ratio.

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Aspect Ratio
16:9
Decimal: 1.778
Preview
16:9

What is Aspect Ratio?

Aspect ratio is the proportional relationship between the width and height of an image or screen. It is typically expressed as two numbers separated by a colon, such as 16:9 or 4:3. The first number represents the width, and the second represents the height.

Understanding aspect ratios is essential for photographers, videographers, graphic designers, and web developers. Different platforms and devices require different aspect ratios for optimal display.

Common Uses for Aspect Ratios

  • YouTube videos: 16:9 (standard widescreen)
  • Instagram feed: 1:1 (square) or 4:5 (portrait)
  • Instagram Stories / TikTok: 9:16 (vertical)
  • Professional photography: 3:2 (DSLR standard)
  • Print documents: A4 paper uses 1.414:1 ratio
  • Cinema: 21:9 (ultrawide cinematic)

How to Calculate Aspect Ratio

To calculate aspect ratio, divide both the width and height by their greatest common divisor (GCD). For example, 1920x1080 pixels: the GCD of 1920 and 1080 is 120. Dividing both by 120 gives 16:9.

Frequently Asked Questions

What is the best aspect ratio for YouTube?

YouTube recommends 16:9 aspect ratio for standard videos. This is the native aspect ratio for most HD, Full HD (1080p), and 4K videos. Common resolutions include 1920x1080 and 3840x2160.

What aspect ratio should I use for Instagram?

Instagram supports multiple aspect ratios: 1:1 (square) for feed posts, 4:5 (portrait) for optimal feed presence, and 9:16 for Stories and Reels. Square images display at 1080x1080 pixels.

How do I resize an image without distortion?

To resize without distortion, maintain the original aspect ratio. Use our Scale Dimensions tool above: enter your original dimensions and one new dimension, and we will calculate the other to preserve the ratio.

What is the difference between 16:9 and 16:10?

16:9 is the standard widescreen format used for HD TVs and most monitors. 16:10 is slightly taller (more vertical space) and was popular for computer monitors and laptops. 16:9 has a decimal ratio of 1.778, while 16:10 is 1.6.

What aspect ratio do DSLR cameras use?

Most DSLR and mirrorless cameras with APS-C or full-frame sensors use a 3:2 aspect ratio, which is inherited from 35mm film. This gives images like 6000x4000 or 3000x2000 pixels.