4:3 Aspect Ratio Calculator: Standard & Fullscreen Dimensions

How to Use Our 4:3 Aspect Ratio Calculator

Our tool is streamlined to give you the numbers you need without any complexity. You only need one measurement to calculate the corresponding 4:3 dimension.

• Enter Width OR Height: Input a single value in pixels (px).

  • If you know the width you need, enter it in the “Width” box. The calculator will solve for the correct height.

  • If you know the height you’re aiming for, enter it in the “Height” box, and the tool will provide the corresponding width.

For example, if you know the standard height for an old presentation slide is 768 pixels, enter “768” into the height field to find its correct 4:3 width.

Understanding Your 4:3 Results

The result from the calculator is the missing dimension required to create a perfect 4:3 rectangle. This was the dominant shape for screens for over half a century.

The 4:3 aspect ratio (pronounced “four-by-three”) describes a screen or image that is 4 units wide for every 3 units of height. Before the shift to widescreen, this was the universal standard for television broadcasts, computer monitors, and early digital cameras. It’s often referred to as “standard definition,” “fullscreen,” or the “Academy ratio.”

The Simple Math Behind 4:3

The calculation relies on a straightforward proportional formula.

• To find the Height when you know the Width:

  Height=4Width×3

• To find the Width when you know the Height:

  Width=3Height×4

This ensures that any image you resize will fit a classic 4:3 frame without being stretched, squashed, or otherwise distorted.

Common 4:3 Resolutions Chart

The 4:3 ratio has been used for countless resolutions over the years. Here are some of the most historically significant and currently relevant ones.

Frequently Asked Questions About the 4:3 Ratio

Why was 4:3 the standard for so long?

The 4:3 aspect ratio’s dominance came directly from the film industry. In the early 20th century, Thomas Edison and William Dickson established that 35mm film stock should have frames that were 4 perforations high. This created an image area with a ratio of approximately 4:3. When television was invented, it was designed to broadcast movies, so it naturally adopted the same 4:3 shape. This standard persisted for decades through the eras of black-and-white TV, color TV, and early computer monitors (CRTs), which were based on television technology.

What devices still use a 4:3 aspect ratio in 2025?

While no longer the standard for TVs or most computer monitors, the 4:3 ratio is far from dead.

• Tablets: The most prominent user is Apple’s iPad line. Apple prefers 4:3 for its tablets because it feels more like a sheet of paper, making it better for web Browse, reading, and document editing in both portrait and landscape orientations.

• Digital Photography: Many Micro Four Thirds camera systems use a native 4:3 sensor.

• Professional Fields: It remains relevant in aviation displays, medical imaging, and industrial monitors where a taller frame is more practical than a wider one.

How do I crop a 16:9 widescreen image to 4:3?

To convert a wide 16:9 image into the taller 4:3 format, you must crop from the sides of the original image.

Concrete Example: Cropping a Widescreen Photo for an iPad

1. Original Image: You have a photo from your smartphone with a 16:9 resolution of 4032×2268 pixels.

2. Target Ratio: You want to make it a fullscreen wallpaper for an iPad, which is 4:3. Let’s say you want the final height to match your photo’s height of 2268 pixels.

3. Calculate New Width: Use the calculator or formula for 4:3. New Width = (2268 / 3) * 4 = 3024 pixels. Your target resolution is 3024×2268.

4. The Crop: Your original photo is 4032 pixels wide, but your target is only 3024 pixels wide. You must crop a total of 4032 - 3024 = 1008 pixels from the sides. In an editing tool, you’d use a 4:3 crop box to frame the most important part of the image, discarding the excess from the left and right.

What happens when I watch a modern movie on a 4:3 screen?

When you play widescreen (16:9 or 21:9) content on a 4:3 display like an iPad, the device will add black bars to the top and bottom of the image. This is called letterboxing. The device does this to show you the full width of the movie without squashing the picture vertically.

Why do old TV shows and games have black bars on my 16:9 TV?

This is the opposite scenario. When you play old 4:3 content on your modern 16:9 widescreen TV, the TV adds black bars to the left and right of the image. This is called pillarboxing. It’s the TV’s way of preserving the original 4:3 shape without stretching it sideways to unnaturally fill the entire screen.

Is 4:3 better for anything today?

Yes, absolutely. While it lost the format war for television, its “taller” shape offers distinct advantages in certain contexts:

• Reading & Web Browse: A 4:3 screen (like an iPad) shows more vertical content, meaning less scrolling.

• Retro Gaming: Playing classic games in their native 4:3 ratio provides the authentic experience the developers intended.

• Photography: The 4:3 frame can be easier to compose for portraits and is less horizontally biased than 16:9.

• Productivity: For applications that benefit from vertical space, like coding or document writing, a 4:3 screen can feel less constrained.

What’s the difference between the 4:3 and 3:2 aspect ratios?

They are very similar, but 3:2 is slightly wider.

• 4:3 (Decimal: 1.33): The standard for iPads, old TVs, and Micro Four Thirds cameras.

• 3:2 (Decimal: 1.5): The standard for 35mm film and full-frame or APS-C DSLR/mirrorless cameras. It’s the native ratio for printing standard 4×6″ photos.

How does the old term “fullscreen” relate to 4:3?

In the era of CRT televisions, “fullscreen” meant a movie or show filled the entire 4:3 screen. Ironically, to make a widescreen movie “fullscreen,” studios would often perform a “pan-and-scan” crop, cutting off the sides of the film to fill the taller TV frame. Today, “fullscreen” has flipped its meaning and generally refers to content filling a modern 16:9 screen.

Can I set a custom 4:3 resolution on my PC?

Yes. If you’re a retro gamer, you can go into your graphics card control panel (NVIDIA, AMD, or Intel) and set a custom 4:3 resolution, such as 1280×960. You can then configure your display’s scaling settings to show this resolution with pillarboxing (black bars) to avoid stretching.

Does 4:3 affect file size?

Not directly. File size is determined by the total number of pixels (resolution) and compression, not the ratio itself. A 1600×1200 (4:3) image has more pixels and will be a larger file than a 1280×720 (16:9) image. The ratio only describes the shape.

Now that you have the correct 4:3 dimensions, you may want to compare them to the modern widescreen standard. Check out our 16:9 Aspect Ratio Calculator to see how it differs. If you’re working with various formats, our general Aspect Ratio Calculator can handle any dimensions you enter.