4:3 Aspect Ratio Calculator for Video

What are the standard 4:3 resolutions?

The standard 4:3 resolutions run from 640 × 480 for standard definition to 2880 × 2160 at 4K height, with 1024 × 768 and 1440 × 1080 in between. Pick the row that matches the frame you're delivering into. The same list covers the 4x3 resolutions people look up by p-number, from 144p to 2160p.

Why is the diagonal always 1.25 times the width?

A 4:3 frame is a 3-4-5 right triangle, so the diagonal is 5 units when the width is 4. That makes the diagonal 1.25 times the width. 640 × 480 has an 800-pixel diagonal and 1440 × 1080 has 1800.

What is 4:3 in pixels?

4:3 in pixels is any width and height where the width is four thirds of the height. Multiply the height by 4 and divide by 3 to get the width, or multiply the width by 3 and divide by 4 to get the height. Then round to an even number, so your editing software doesn't complain.

Here are four worked examples:

• Height 1080: 1080 × 4 ÷ 3 = 1440, so the frame is 1440 × 1080. No rounding needed.
• Width 1024: 1024 × 3 ÷ 4 = 768, so the frame is 1024 × 768.
• Width 1500: 1500 × 3 ÷ 4 = 1125. That's odd, so video uses 1126 (1124 is just as close).
• Height 500: 500 × 4 ÷ 3 = 666.67. The nearest even number is 666, so the frame is 666 × 500.

To check a size you already have, divide width by height. 1440 ÷ 1080 = 1.333, so it's 4:3. 720 × 480 gives 1.5, which is 3:2.

What is 480p in 4:3, and how big is SD video?

480p in 4:3 is 640 × 480. The 16:9 version of 480p is 854 × 480, so the 480 only describes the height ^[1]. Broadcast TV was 4:3 until widescreen took over, so archive tapes and DVDs of older shows are standard definition at 4:3, and that is the old TV shape.

On paper neither stored frame is 4:3, because 720 × 480 divides to 1.5 and 720 × 576 to 1.25. The pixels are not square, and editors correct for that with a pixel aspect ratio ^[2]. Use the square-pixel column when you need a canvas for the web or for a project with square pixels.

Where is 4:3 still used?

4:3 is still used wherever old material or old hardware is involved. These are the cases you're most likely to meet:

• Archive footage: Older broadcasts, home video and DVDs are 4:3 and are often kept that way for restoration.
• Projectors and presentation screens: 1024 × 768 (XGA) is still a common size.
• Legacy capture and camera feeds: Some capture cards and security cameras output 640 × 480 or 1024 × 768.
• Deliberate period looks: Editors choose 4:3 to match old material or to give a modern project a retro feel.

For panel sizes and diagonals on actual displays, use the monitor calculator.

What size is 4:3 inside a 1080p or 4K timeline?

A 4:3 picture in a 1080p timeline is 1440 × 1080, with a 240-pixel bar on the left and right. In a 4K UHD timeline it's 2880 × 2160, with 480-pixel bars. Bars at the sides of a picture are called pillarboxes.

The picture always takes 75% of the frame width, so the bars are 12.5% of the width on each side. You can also fill the frame by cropping: a 4:3 clip cropped to 16:9 keeps the full width and loses 25% of the height. Pillarbox when you can't lose picture. For other 16:9 sizes, use the 16:9 calculator.

What is the 1440 × 1080 aspect ratio?

1440 × 1080 is a 4:3 aspect ratio when the pixels are square, but HDV video of the same size plays back as 16:9. HDV camcorders record 1440 × 1080 with pixels 1.333 times wider than they are tall, so the picture stretches to 1920 × 1080 on playback ^[3].

The numbers are the same and the shapes are different. Check the pixel aspect ratio of the clip in your editor: Square Pixels means 4:3 and 1.333 means 16:9. The anamorphic desqueeze calculator handles the stretch maths for other squeeze factors.

What is the difference between 4:3 and the 1.37:1 Academy ratio?

The 1.37:1 Academy ratio is about 3% wider than 4:3, so a 1.375:1 frame at 1080 tall is 1485 wide against 1440 ^[4]. The two are easy to mix up because film frames of that era were close to 4:3, which is why classic movies nearly fill an old TV screen.

Archive scans are labelled 4:3 or 1.37:1 depending on who made them. For film-scan sizes, use the 1.375:1 Academy ratio calculator.

How does 4:3 compare with 16:9?

16:9 is the better choice for almost all modern video, and 4:3 is the better choice for archive and legacy work. At the same height, 16:9 is 33% wider, which is 1920 against 1440 at 1080 tall. A 16:9 picture on a 4:3 screen does the reverse and leaves bars above and below, so a 1440-wide screen shows it at 1440 × 810.

The full verdict is in 16:9 versus 4:3, which is better, and you can lay the two shapes over each other in the aspect ratio visualizer. 4:3 is also close to 3:2, which is 12.5% wider (1620 against 1440 at 1080 tall). For photo sizes in 3:2, use the 3:2 photography calculator.

What are the 3:4 sizes?

3:4 is 4:3 turned on its side, so the width and height swap. Multiply the width by 4 and divide by 3 to get the height.