4:3 Aspect Ratio Calculator
A 4:3 frame is four units wide for every three high. Common exact sizes include 640 × 480 (VGA), 1024 × 768 (XGA) and 1600 × 1200 (UXGA). Enter a width or height to calculate a matching 4:3 size without stretching.
Calculate 4:3
What does a 4:3 aspect ratio mean?
A 4:3 frame is four units wide for every three units high. Its decimal ratio is approximately 1.3333. Compared with 16:9 it is less wide, giving photographs, slides and classic video a more compact landscape composition.
Exact 4:3 dimensions include 640 × 480, 800 × 600, 1024 × 768, 1600 × 1200 and 2048 × 1536. The same geometry rotated becomes 3:4 portrait, so orientation matters when writing the ratio.
How to calculate 4:3 dimensions
Find height by multiplying width by 3/4. Find width by multiplying height by 4/3.
height = width × 3 ÷ 4width = height × 4 ÷ 3Example: 1600 × 3 ÷ 4 = 1200.
Choose dimensions divisible by four when you want the calculated height to remain a whole number without rounding.
4:3 vs. 16:9
4:3 is 1.3333:1; 16:9 is about 1.7778:1. Converting a 4:3 frame to fill 16:9 removes content from the top and bottom. Fitting the full frame creates space on the left and right, often called pillarboxing in video.
Do not stretch 4:3 horizontally to fill 16:9. Use a deliberate crop, padding or redesigned composition.
A note about pixel aspect ratio
Most modern web images use square pixels, so pixel dimensions directly determine display aspect ratio. Some older video formats use non-square pixels. In those workflows, stored dimensions such as 1440 × 1080 may be displayed as a different shape because metadata tells the player how wide each pixel should appear. This calculator assumes square pixels.
Common exact 4:3 resolutions
These established pixel dimensions all reduce exactly to 4:3. The labels describe historical display standards; they are reference sizes, not required camera or video export settings.
| Resolution | Dimensions | Typical context |
|---|---|---|
| VGA | 640 × 480 px | Classic low-resolution displays |
| SVGA | 800 × 600 px | Legacy computer displays |
| XGA | 1024 × 768 px | Older monitors and projectors |
| UXGA | 1600 × 1200 px | Higher-resolution 4:3 displays |
| QXGA | 2048 × 1536 px | High-pixel-count 4:3 imagery |
A 4:3 aspect ratio describes shape, not image quality. For example, 640 × 480 and 2048 × 1536 share the same proportions but have very different pixel counts.
More calculated 4:3 dimensions
The calculator also generates other widths below. Some calculated heights must be rounded to whole pixels and are marked approximately 4:3. Use an exact resolution above when the dimensions must remain strictly 4:3.
| Width | Height | Ratio |
|---|
Next steps for 4:3 content
For older video, distinguish stored pixel dimensions from displayed shape with the pixel aspect ratio calculator. To preserve a 4:3 picture inside a fixed widescreen frame, calculate the side bars instead of stretching it.
Check an existing photo with the image ratio checker, or compare a 4:3 source with a 16:9 target before cropping.
Frequently asked questions
Is 1024 × 768 a 4:3 resolution?
Yes. Dividing both dimensions by 256 gives 4:3.
Are 4:3 and 3:4 the same?
They use the same proportions but different orientations. 4:3 is landscape; 3:4 is portrait.
How do I turn 4:3 into 16:9?
Crop the top and bottom to fill a 16:9 frame, or keep the complete 4:3 image and add side space. Avoid stretching the width independently.
Does 4:3 mean standard definition?
No. A ratio does not define quality. A 4:3 file can be low or high resolution depending on its pixel dimensions.