What is an aspect ratio?

An aspect ratio is the proportional relationship between the width and height of an image or screen, expressed as two numbers separated by a colon. For example, 16:9 means the width is 16 units for every 9 units of height. It describes the shape, not the size.

How do I resize an image without distortion?

Enter the original width and height, then change only one dimension (width or height). The calculator automatically computes the other dimension to maintain the aspect ratio, ensuring the image is not stretched or squished.

What is the aspect ratio of 1920×1080?

1920×1080 simplifies to 16:9. This is the standard widescreen ratio used by Full HD televisions, most laptop screens, and YouTube videos. The decimal equivalent is approximately 1.7778.

What is the difference between 16:9 and 4:3?

16:9 is widescreen (wider than it is tall), used for modern TVs and YouTube. 4:3 is closer to square, used for classic TV, iPad screens, and some older video formats. 16:9 is about 78% wider relative to its height than 4:3.

Can I use this for vertical video (TikTok, Reels)?

Yes. Select the 9:16 preset, which is the vertical equivalent of 16:9. Enter your height (e.g., 1920 for a full HD vertical video) and the width calculates to 1080.

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Aspect Ratio Calculator

To calculate aspect ratio, divide width by height and simplify. For 1920×1080, the ratio is 16:9. To find a missing dimension, enter the known ratio and one dimension: for 16:9 at 1280 pixels wide, the height is 1280 × 9/16 = 720 pixels. Our free calculator handles this instantly.

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What is Aspect Ratio Calculator?

An aspect ratio calculator is an online tool that computes the proportional relationship between width and height of images, videos, and screens, and calculates missing dimensions when resizing while maintaining the correct ratio.

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These tools work great alongside Aspect Ratio Calculator:

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Getting the aspect ratio wrong means distorted images, letterboxed videos, and cropped content. This free aspect ratio calculator makes it impossible to get it wrong — enter your dimensions, pick a common ratio preset, and get the exact pixel values you need for any platform, device, or resolution.

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