# 4:3 Aspect Ratio Calculator

URL: https://speedycalculator.com/calculators/other/4-3-aspect-ratio/
Last updated: 2026-10-30

> The 4:3 calculator works out the matching height or width in the classic 4:3 format of phone photos, older TVs and monitors, checks whether a size is 4:3 and shows the largest 4:3 crop of any picture.

## Inputs

- What do you want to do?
- Width — Pixels, or any length unit – the result uses the same unit.
- Height — Pixels, or any length unit.

## Results

- Height at 4:3
- Nearest even whole-pixel height
- Width at 4:3
- Nearest even whole-pixel width
- Is it 4:3?
- Width ÷ height
- Difference from 4:3
- Largest 4:3 crop – width
- Largest 4:3 crop – height
- Share of the picture kept by the crop
- Pixel count (if the values are pixels)

## Formula

```
Height = width × 3 ÷ 4 · Width = height × 4 ÷ 3 · a size is 4:3 when width ÷ height = 1.3333
```

## Explanation

The 4:3 ratio (1.33:1) is the classic "full screen" shape. It was the frame of silent and early sound films, of analogue television for half a century and of CRT computer monitors (640 × 480, 800 × 600, 1024 × 768). It is far from obsolete: most phone cameras, compact cameras and Micro Four Thirds bodies still record 4:3 photos, and iPads use a similar shape.

To work out a 4:3 size, multiply the width by 3/4 to get the height, or the height by 4/3 to get the width. A 12-megapixel phone photo is 4000 × 3000, and the 4:3 frame makes better use of a round lens image than a wide one, which is why sensors keep it.

The check mode tells you whether a picture is 4:3 and how to crop a wider image to 4:3 – for example to print a 16:9 frame grab on a 4:3 page or to match old archive footage in an edit.

### How to use the 4:3 Aspect Ratio Calculator

- **What do you want to do?**
- **Width** — Pixels, or any length unit – the result uses the same unit.
- **Height** — Pixels, or any length unit.

Results update as you type, every field has its own unit menu, and everything is calculated in your browser.

### How it works

Choose a mode and enter the size. Height = width × 3/4, width = height × 4/3, and a picture is 4:3 when width ÷ height is 1.3333; the crop keeps the side that limits the frame.

### Worked example

For a 1024 px wide 4:3 frame the height is 1024 × 3 ÷ 4 = 768 px. A 1920 × 1080 video frame is wider (1.778 > 1.333), so the largest 4:3 crop keeps the 1080 height and a width of 1080 × 4 ÷ 3 = 1440 px.

### Common 4:3 sizes

NameResolutionPixelsVGA640 × 4800.31 MPSVGA800 × 6000.48 MPXGA1024 × 7680.79 MPUXGA1600 × 12001.92 MPQXGA2048 × 15363.15 MP12 MP photo4000 × 300012.0 MP

### Inputs explained

FieldWhat to enterWhat do you want to do?Choose one: Find the height from a width, Find the width from a height, Check a size and find the largest 4:3 cropWidthA number. Pixels, or any length unit – the result uses the same unit.HeightA number. Pixels, or any length unit.

### What each result means

- **Height at 4:3** = [Width]×3÷4
- **Nearest even whole-pixel height** = 2×round([Width]×3÷4÷2)
- **Width at 4:3** = [Height]×4÷3
- **Nearest even whole-pixel width** = 2×round([Height]×4÷3÷2)
- **Width ÷ height** = [Width]÷[Height]
- **Difference from 4:3** = ([Width]÷[Height]÷(4÷3) - 1)×100

## Worked example

Inputs — What do you want to do?: Find the height from a width; Width: 1,024.

Results — **Height at 4:3 = 768**; Nearest even whole-pixel height = 768; Pixel count (if the values are pixels) = 0.786 MP.

## Key terms

- **4:3**: The 1.33:1 "standard" or "full-screen" aspect ratio.
- **Pillarboxing**: Bars at the left and right when 4:3 content is shown on a widescreen.
- **Academy ratio**: The 1.375:1 film frame close to 4:3, standard from 1932 to the 1950s.

## FAQ

**How do I calculate the height for 4:3?**
Multiply the width by 3 and divide by 4. A 1024 px width gives 768 px.

**How do I calculate the width for 4:3?**
Multiply the height by 4/3. A 1440 px height gives 1920 px.

**What is 4:3 as a decimal?**
1.3333 (1.33:1).

**Is 4:3 better for photos?**
Many photographers like it for portraits and prints because it is closer to common paper shapes; phones use it to capture the most sensor area.

**How much of a 16:9 frame is kept when cropping to 4:3?**
75%: 1920 × 1080 becomes 1440 × 1080.

**Which resolutions are 4:3?**
640 × 480, 800 × 600, 1024 × 768, 1600 × 1200 and 4000 × 3000, among others.


## Sources

- [Wikipedia – Aspect ratio (image)](https://en.wikipedia.org/wiki/Aspect_ratio_(image))
- [Wikipedia – 4:3 aspect ratio](https://en.wikipedia.org/wiki/4:3_aspect_ratio)
- [Wikipedia – Four Thirds system](https://en.wikipedia.org/wiki/Four_Thirds_system)