Find Aspect Ratio

Video Ratios & Screen Fit.

Explore cinema formats, television history, vertical mobile video scaling, and how displays utilize active screen area.

Want to simulate screen fit?

Use the **Screen Simulator** tool below to match cinematic or smartphone formats inside computer monitors, televisions, or smartphones to check exact percentage screen coverage.

The Standard Screen Formats

Unlike static print files, digital videos have to run on active hardware displays with fixed physical aspect ratios. The ratio of the video content and the screen determines how the video is displayed:

Cinema standards (1.85:1 and 2.39:1)

Cinema uses ultra-widescreen proportions. **1.85:1 (Flat)** is common for standard theatrical releases, while **2.39:1 (Anamorphic Scope)** is the iconic wide cinematic look used for epic features.

Television standards (4:3 and 16:9)

Standard Definition broadcast signals were fixed to **4:3**. High Definition standards updated this broadcast standard to **16:9** (1.78:1) to accommodate wider landscapes.

Understanding Black Bars

When video aspect ratios do not align with screen ratios, hardware and players inject black padding borders so the visual content remains un-cropped and proportional:

Letterboxing (Top & Bottom Bars)

Occurs when the content is **wider** than the screen (e.g. playing a 2.39:1 cinema movie on a standard 16:9 TV). The width of the video fits the screen width, leaving black strips on the top and bottom.

Pillarboxing (Left & Right Bars)

Occurs when the content is **taller/narrower** than the screen (e.g. playing a vertical 9:16 TikTok story on a horizontal widescreen TV, or watching a vintage 4:3 movie on a modern display). The height of the video fits the screen height, leaving black strips on the left and right sides.

Windowboxing (All-Sides Bars)

A combination of both, resulting in a small box bordered by black on all four sides. This occurs when 4:3 footage that was previously letterboxed into a 16:9 signal is played back on a 4:3 display.

Interactive Screen Simulator.

Lock Aspect Ratio
Decimal Ratio: 1.78:1 GCD Status: 120
Live Shape Visualizer
16:9
1920 × 1080
RESOLVER TV
findaspectratio.com
* Note: Float values like 19.5:9 (modern phones) are fully supported and will not be truncated. Lock aspect ratio keeps the dimensions locked together.
Social Media Cheat Sheet

Standard Platform Dimensions.

A comprehensive database of social media asset sizes, dimensions, and standard aspect ratios. Use the search field below to instantly filter entries.

Platform Asset Type Recommended Pixels Aspect Ratio Required Fit
Instagram Square Post 1080 × 1080 px 1:1 Standard Grid Feed
Instagram Portrait Post 1080 × 1350 px 4:5 Recommended Feed Size
Instagram Reels / Stories 1080 × 1920 px 9:16 Vertical Fullscreen
YouTube Standard Video 1920 × 1080 px 16:9 Full HD standard (1080p)
YouTube Thumbnail 1280 × 720 px 16:9 Max file size 2MB
YouTube Shorts Video 1080 × 1920 px 9:16 Vertical format
TikTok Video 1080 × 1920 px 9:16 Native fullscreen view
TikTok Profile Photo 200 × 200 px 1:1 Rendered as circle
Twitter / X Landscape Post 1600 × 900 px 16:9 Best for feed display
Twitter / X Square Post 1080 × 1080 px 1:1 Renders fully in feed
Pinterest Standard Pin 1000 × 1500 px 2:3 Optimized for vertical feed
LinkedIn Profile Banner 1584 × 396 px 4:1 Aspect ratio exactly 4:1
The Math Engine

How Aspect Ratio is Calculated.

An aspect ratio represents the proportional relationship between a shape's width and its height. Mathematically, it is written as a simplified fraction quotient of $W:H$.

If you have a set of pixel dimensions ($Width \times Height$) and want to determine their simplest integer aspect ratio, you must find the **Greatest Common Divisor (GCD)** of both numbers and divide each dimension by it:

Ratio Width = Width ÷ GCD(Width, Height)
Ratio Height = Height ÷ GCD(Width, Height)

For instance, for a standard Full HD display size of 1920 × 1080 px, the Greatest Common Divisor is 120:

1920 ÷ 120 = 16
1080 ÷ 120 = 9
Result = 16:9
euclidean-gcd.js
function calculateGCD(width, height) {
  width = Math.abs(width);
  height = Math.abs(height);
  
  // Euclid's subtraction algorithm
  while (height) {
    const temp = height;
    height = width % height;
    width = temp;
  }
  return width;
}
 
// Example Usage:
const gcd = calculateGCD(1920, 1080); // returns 120
Our codebase implements an advanced version of this classical Euclidean loop, capable of parsing floating-point numbers like 19.5:9 or 2.39:1 by dynamic multiplier shifts prior to computing modulo residues.