Free Tool

Aspect Ratio Calculator

Instantly calculate dimensions and visualize aspect ratios for your next project.


Result: 16:9
1920px 1080px

Why Aspect Ratio Matters

Understanding aspect ratio is fundamental for digital creators. It is practically the DNA of your visual content. Whether you are a videographer trying to avoid "black bars" (letterboxing), a developer building a responsive website, or a social media manager ensuring your posts don't get cropped, getting the numbers right is essential. For developers embedding content, these ratios ensure your iframes remain responsive and visually balanced.

Common Aspect Ratios Explained

Navigating the world of pixels can be confusing. Here is a definitive guide to the aspect ratios you see every day, from social media scrolling to cinematic experiences:

Platform Cheat Sheet
  • Instagram / Facebook Feed: 4:5 (Portrait) or 1:1 (Square)
  • TikTok / Reels / YouTube Shorts: 9:16 (Vertical Fullscreen)
  • YouTube / TV / Monitors: 16:9 (Standard Widescreen)
  • Cinematic Video: 21:9 (Ultrawide)

16:9 (Widescreen)

The global standard for HDTV, Full HD, and 4K Ultra HD. It's used by YouTube, Netflix, and almost all computer monitors.
Common Resolutions: 1920x1080, 1280x720, 3840x2160

9:16 (Vertical)

The standard for mobile-first short-form video content like TikTok, Instagram Reels, and YouTube Shorts.
Common Resolutions: 1080x1920, 720x1280

4:3 (Standard)

The classic aspect ratio for old CRT TVs and 35mm film. Still widely used in photography and some tablets (like iPads).
Common Resolutions: 1024x768, 1600x1200

1:1 (Square)

Perfectly equal width and height. Popularized by Instagram for feed posts and generic social media avatars.
Common Resolutions: 1080x1080, 500x500

21:9 (Ultrawide)

Often referred to as CinemaScope. It provides a deeper, more immersive field of view, common in major motion pictures.
Common Resolutions: 2560x1080, 3440x1440

You Asked

Frequently Asked Questions

How do I calculate aspect ratio from resolution?

To find the aspect ratio, divide the width by the height. For example, 1920/1080 = 1.777. Since 16/9 is also 1.777, the ratio is 16:9.

Mathematically, you find the Greatest Common Divisor (GCD) of both the width and height, then divide both numbers by the GCD.

What is the "Golden Ratio"?

The Golden Ratio is approximately 1.618:1. It is a mathematical ratio found in nature and art that is believed to be aesthetically pleasing. It is slightly wider than 3:2 and slightly narrower than 16:9.

What ratio should I use for YouTube?

YouTube's standard player is 16:9. If you upload other ratios like 4:3 or 1:1, YouTube will add black bars (pillarboxing) to the sides to fit the 16:9 player. For YouTube Shorts, use 9:16.

Can I resize images without changing aspect ratio?

Yes! That is exactly what this calculator helps you do. If you lock the aspect ratio (e.g. 16:9), changing the width will automatically calculate the correct height to maintain the exact same shape, preventing distortion.

Tool provided by Abhishek Dey Roy's Free SEO Tools