What is the 16:9 aspect ratio?
16:9 means the frame is 16 units wide for every 9 units tall. As a decimal it is about 1.7778, so the width is roughly 1.78 times the height. It is the standard shape for HD and 4K television, most computer monitors and laptops, presentation software, and landscape online video.
Because so many screens share this shape, 16:9 is the safest default for anything people will watch full-screen in landscape. Content in this shape fills a typical TV or monitor without black bars.
How to calculate 16:9 dimensions
height = width × 9 ÷ 16width = height × 16 ÷ 916 ÷ 9 ≈ 1.7778For example, a 1920 px wide frame needs 1920 × 9 ÷ 16 = 1080 px of height. A 900 px tall frame needs 900 × 16 ÷ 9 = 1600 px of width.
If the width is a multiple of 16 (640, 1280, 1920, 2560, 3840), the height comes out as a whole number with no rounding. Video encoders also like dimensions that are multiples of 8 or 16.
Where 16:9 is used
- Landscape video: YouTube, Vimeo, streaming services and most video editors default to 16:9.
- Thumbnails: video thumbnails are usually 1280 × 720 so they match the player shape.
- Slides: PowerPoint, Keynote and Google Slides use 16:9 as the default widescreen layout.
- Websites: responsive video embeds and hero images often use
aspect-ratio: 16 / 9in CSS.
16:9 in CSS
To keep an element at 16:9 at any width, use the CSS aspect-ratio property: aspect-ratio: 16 / 9;. Set a width (for example width: 100%) and the browser calculates the height for you.
Frequently asked questions
Is 1920×1080 a 16:9 resolution?
Yes. 1920 ÷ 1080 = 1.7778, which is exactly 16:9. It is the most common Full HD resolution.
Is 16:9 the same as 1.78:1?
Yes. 1.78:1 is 16:9 written as a rounded decimal. Film and broadcast people often use the decimal form.
Is 1366×768 16:9?
Almost. 1366 ÷ 768 ≈ 1.7786, which is very close to 16:9 but not exact. Exact 16:9 at that width would be 1366 × 768.375, so the screen is rounded to whole pixels.
What is the vertical version of 16:9?
Swap the numbers to get 9:16, the shape used by Reels, TikTok and Shorts. See the 9:16 calculator.