CSS Aspect Ratio Calculator

Calculate aspect ratios and generate CSS code for responsive web design

Calculate CSS Aspect Ratio

Original Dimensions

Target Dimensions

Aspect Ratio Results

16:9
Ratio
1.7778
Decimal
56.25%
Padding-bottom

Target Dimensions

Width: 800px × Height: 450px

Closest Common Ratio

16:9 - Widescreen (16:9)

Video, modern displays

Generated CSS Code

/* Method 1: Using aspect-ratio property (modern browsers) */
.aspect-ratio-container {
  width: 800px;
  aspect-ratio: 16/9;
}

/* Method 2: Using padding-bottom technique (legacy support) */
.aspect-ratio-container {
  position: relative;
  width: 800px;
  height: 0;
  padding-bottom: 56.2500%;
}

.aspect-ratio-content {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

/* Method 3: Fixed dimensions */
.fixed-aspect-ratio {
  width: 800px;
  height: 450px;
}

Visual Preview

Original Ratio

16:9

Target Size Preview

800 × 450

Scaled to fit preview

CSS Implementation Methods

Modern: aspect-ratio

CSS property for modern browsers

aspect-ratio: 16/9;

Legacy: padding-bottom

Percentage-based technique

padding-bottom: 56.25%;

Fixed: width & height

Explicit dimensions

width: 800px; height: 450px;

Common Aspect Ratios

16:9
Video, modern displays
1.778
16:10
Laptop displays
1.600
4:3
Classic monitors, tablets
1.333
3:2
Digital cameras, prints
1.500
1:1
Social media, profiles
1.000
21:9
Cinematic, ultrawide monitors
2.333
2:1
Website banners, covers
2.000
5:4
Traditional portraits
1.250

Understanding CSS Aspect Ratios

What is CSS Aspect Ratio?

CSS aspect ratio is the proportional relationship between the width and height of an element. It's crucial for responsive design, ensuring elements maintain their intended proportions across different screen sizes and devices.

Why Use Aspect Ratios?

  • Maintain consistent visual proportions
  • Prevent layout shifts during loading
  • Create responsive media containers
  • Ensure consistent UI across devices

Implementation Methods

Modern CSS (aspect-ratio)

.container {
  aspect-ratio: 16/9;
  width: 100%;
}

Legacy Support (padding-bottom)

.container {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%;
}