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
| Name | Resolution | Pixels |
|---|---|---|
| VGA | 640 × 480 | 0.31 MP |
| SVGA | 800 × 600 | 0.48 MP |
| XGA | 1024 × 768 | 0.79 MP |
| UXGA | 1600 × 1200 | 1.92 MP |
| QXGA | 2048 × 1536 | 3.15 MP |
| 12 MP photo | 4000 × 3000 | 12.0 MP |
Inputs explained
| Field | What to enter |
|---|---|
| What 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 crop |
| Width | A number. Pixels, or any length unit – the result uses the same unit. |
| Height | A 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
Formula
Height = width × 3 ÷ 4 · Width = height × 4 ÷ 3 · a size is 4:3 when width ÷ height = 1.3333
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.
Frequently asked questions
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.