Aspect Ratio Calculator

Common Aspect Ratios

Aspect ratios define the proportional relationship between an image's width and height. The most common ratios you will encounter include:

• 16:9 -- The standard widescreen ratio used by most monitors, TVs, and video platforms like YouTube.
• 4:3 -- The classic TV and monitor ratio, still used in presentations and some tablets.
• 1:1 -- A perfect square, popular on Instagram and profile pictures.
• 21:9 -- Ultra-wide ratio used in cinematic displays and gaming monitors.
• 9:16 -- Vertical video ratio used for stories, reels, and TikTok.
• 3:2 -- Common in photography and some laptop displays.

Aspect Ratios for Social Media

Each social media platform has recommended image and video dimensions. Using the correct aspect ratio ensures your content displays without cropping or black bars.

• Instagram Post: 1:1 (1080x1080) or 4:5 (1080x1350)
• Instagram Story / Reels: 9:16 (1080x1920)
• YouTube Video: 16:9 (1920x1080 or 3840x2160)
• YouTube Thumbnail: 16:9 (1280x720)
• Twitter / X Post: 16:9 (1200x675)
• Facebook Cover: approximately 2.63:1 (820x312)
• LinkedIn Post: approximately 1.91:1 (1200x627)

How to Calculate Aspect Ratio

To find the aspect ratio of any image or screen, follow these steps:

1. Note the width and height in pixels (e.g., 1920 x 1080).
2. Find the greatest common divisor (GCD) of both numbers. For 1920 and 1080, the GCD is 120.
3. Divide both width and height by the GCD: 1920 / 120 = 16, 1080 / 120 = 9. The aspect ratio is 16:9.

This calculator performs the GCD calculation automatically. Just enter your dimensions and the simplified ratio appears instantly.

Frequently Asked Questions

What is an aspect ratio?

An aspect ratio is the proportional relationship between the width and height of a rectangle -- such as an image, video, or screen. It is expressed as two numbers separated by a colon, like 16:9 or 4:3. It describes the shape, not the size.

How do I calculate aspect ratio from width and height?

Divide both the width and height by their greatest common divisor (GCD). For example, a 1920x1080 image has a GCD of 120. Dividing both by 120 gives 16:9. This calculator does this automatically when you enter dimensions.

What is the most common aspect ratio for video?

16:9 is the standard aspect ratio for most video content today. It is used by YouTube, streaming services, broadcast TV, and HD/4K displays (1920x1080, 3840x2160). For vertical video on mobile platforms, 9:16 is used.

What aspect ratio should I use for social media?

It depends on the platform. Instagram posts use 1:1 (square) or 4:5 (portrait). Stories and Reels use 9:16. YouTube and Twitter use 16:9. Always check the platform's current guidelines, as recommendations can change.