4:3 aspect ratio
4:3 is the traditional television and monitor shape, with a decimal value of 1.3333. It survives in tablets, in some camera sensors and in documents.
At a glance
- Ratio
- 4:3
- Decimal value
- 1.3333 (width divided by height)
- CSS aspect-ratio
- aspect-ratio: 4 / 3;
- Common pixel dimensions
- 640 x 480, 800 x 600, 1024 x 768, 1600 x 1200, 2048 x 1536
- Suits
- Tablets, document pages, older photo libraries and slide decks that will be printed
- Struggles with
- Video for modern displays and anything designed to fill a widescreen panel
In detail
The ratio came out of early cinema and was carried into television, then into computer monitors, and it dominated screens for most of a century. Its resolution ladder is as tidy as the widescreen one, running through 640 by 480, 800 by 600, 1024 by 768 and 1600 by 1200, each an exact 4:3 with no rounding.
It has not disappeared. Many tablets use it or something close to it, because a squarer screen is better for reading a page than a wide one. Several camera systems shoot it natively, and it remains the default for a document page rendered to an image, since a page of text is always closer to square than to widescreen.
Against 16:9 the difference is larger than the numbers suggest. At the same width, a 4:3 frame is a third taller than a 16:9 one, so a 4:3 image placed in a widescreen frame loses a quarter of its height to a crop, or gains vertical bars on both sides if it is fitted instead.
The cropper here has a 4:3 ratio preset, so converting a widescreen source is a single choice rather than a calculation. Going the other way, from 4:3 to 16:9, always removes content, which is worth deciding deliberately rather than discovering after the export.
Examples
640 x 480 0.31 MP
800 x 600 0.48 MP
1024 x 768 0.79 MP
1600 x 1200 1.92 MP
2048 x 1536 3.15 MP1600 wide at 16:9 -> 900 tall
1600 wide at 4:3 -> 1200 tall
difference -> 300 pixels, a third more heightThings that catch people out
- Fitting 4:3 content into a 16:9 frame either pillarboxes it or crops a quarter of its height. Decide which before exporting, not in the player.
- Stretching rather than cropping between the two is the most visible mistake in video, because it widens every face by a third.
- 4:3 and 5:4 are both squarish and different. A 1280 by 1024 monitor is 5:4, not 4:3, and content authored for one is letterboxed on the other.
Try it: Aspect Ratio Calculator
Enter a width and a height, or a ratio and one dimension, and it solves the missing one, simplifies the ratio, counts the megapixels and gives you a copyable CSS value.
Aspect Ratio Calculator
LOCAL · Browser-OnlyCalculate and convert aspect ratios for images, videos, and screens
1920 x 1080px · 16:9 · 1.7778:1
Common Aspect Ratios Reference
| Ratio | Decimal | Common Use |
|---|---|---|
| 16:9 | 1.778 | Widescreen TV, YouTube, monitors |
| 4:3 | 1.333 | Classic TV, iPad, presentations |
| 1:1 | 1.000 | Instagram square, profile pictures |
| 21:9 | 2.333 | Ultrawide monitors, cinema |
| 9:16 | 0.563 | Phone vertical, TikTok, Reels |
| 3:2 | 1.500 | 35mm photography, MacBook |
| 2:3 | 0.667 | Portrait photography, posters |
| 5:4 | 1.250 | Large format photography, older monitors |
| 32:9 | 3.556 | Super ultrawide monitors |
| 2.39:1 | 2.390 | Anamorphic cinema, widescreen films |
Related Image and canvas sizes
All image and canvas sizes →16:9 aspect ratio
Where the 16:9 ratio came from, the pixel dimensions that hit it exactly, what it suits, and the places where a widescreen frame is the wrong shape.
5:4 aspect ratio
The 1.25 ratio behind 1280 by 1024 monitors and 8 by 10 inch prints, why it caused distorted desktops for years, and where it still applies.
3:2 aspect ratio
The 1.5 ratio inherited from the 35mm film frame, the sensors and laptop screens that still use it, and how it sits between 4:3 and 16:9.
1:1 aspect ratio
The square ratio, its origins in medium format film and social feeds, why it is the most reusable shape, and where it wastes space.
21:9 aspect ratio
The 21:9 marketing label at 2.3333, the 43:18 and 64:27 shapes that real ultrawide panels actually use, and how to design for the gap between them.
9:16 aspect ratio
The vertical video ratio at 0.5625, its exact inverse relationship with widescreen, and why modern phone screens are taller than it.
Tools for this
- Aspect Ratio Calculator Free online aspect ratio calculator - calculate and convert aspect ratios for images, videos, and screens
- Image Cropper Free online image cropper - crop images with preset aspect ratios and free-form selection