---
title: "Short note: Resolution and aspect ratio"
subject: "Computer Graphics"
chapter: 1
key: "semester_5/computer_graphics:short-note-resolution-aspect-ratio"
source: https://www.bctengineer.com/q/semester_5/computer_graphics/short-note-resolution-aspect-ratio
site: BCT Engineering
---

# Short note: Resolution and aspect ratio

Computer Graphics · Chapter 1: Introduction and Application

- Asked in: 2067 Mangsir (old course), 5 marks
- Video: [Introduction to Pixels, Resolution, PPI & Aspect Ratio | Computer Graphics](https://www.youtube.com/watch?v=djKXBDuJOqo) — Gate Smashers
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/computer_graphics/short-note-resolution-aspect-ratio
- Whole chapter: https://www.bctengineer.com/md/semester_5/computer_graphics/chapter-1

## Question

Write a short note on resolution and aspect ratio of a monitor.

## Short answer

Resolution is the number of pixels displayed as columns × rows, e.g. 1024×768. Higher resolution yields more detail but requires a larger frame buffer. Aspect ratio is width-to-height ratio, such as 4:3 or 16:9, and mismatch causes stretching.

## Answer

#### Resolution
**Resolution** is the number of pixels that can be displayed on the screen, given as columns × rows (e.g. 1024 × 768, 1920 × 1080). It can also be given as pixels per inch (PPI/DPI). Higher resolution means more pixels, finer detail and a sharper picture, but needs a larger frame buffer.

```text
Frame buffer size = width × height × bits per pixel
Example: 1024 × 768 × 24 = 18,874,368 bits = 2.25 MB
```

#### Aspect ratio
**Aspect ratio** is the ratio of the width to the height of the screen (or image). For 1024 × 768 it is 1024 : 768 = 4 : 3. Other common values are 16 : 9 (1920 × 1080) and 16 : 10.

The aspect ratio is also the ratio of the number of horizontal points to vertical points needed to produce lines of equal length in both directions. If the aspect ratio of an image does not match the screen, the image looks stretched or has black bars.

Resizing keeping the aspect ratio: new height = new width × (old height / old width).

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Resolution is
   A. Width/height ratio
   B. Refresh rate
   C. Screen diagonal
   D. Number of pixels displayed, as columns x rows
   Answer: D. Resolution counts pixels. (Key point: Resolution)

2. Aspect ratio of 1024 x 768 is
   A. 4 : 3
   B. 16 : 9
   C. 16 : 10
   D. 1 : 1
   Answer: A. 1024:768 = 4:3. (Key point: Aspect ratio)

3. Frame buffer size formula is
   A. width + height
   B. width x height x bits per pixel
   C. width x height only
   D. bits per pixel x fps
   Answer: B. Higher resolution needs more memory. (Key point: Frame buffer)

4. Higher resolution gives
   A. coarser detail
   B. smaller buffer
   C. finer detail but larger frame buffer
   D. lower sharpness
   Answer: C. More pixels mean sharper image and more memory. (Key point: Effect)

## Related in Computer Graphics

- [Resize image keeping aspect ratio](https://www.bctengineer.com/question.md?key=semester_5%2Fcomputer_graphics%3Aresize-image-aspect-ratio) — Computer Graphics, chapter 1

## Related in other subjects

- [Mesh quality: skewness, aspect ratio, orthogonality](https://www.bctengineer.com/question.md?key=semester_7%2Fapplied_computational_fluid_dynamics%3Amesh-quality-metrics) — Applied Computational Fluid Dynamics, chapter 4
- [Skewness and aspect ratio of cells](https://www.bctengineer.com/question.md?key=semester_7%2Fapplied_computational_fluid_dynamics%3Askewness-aspect-ratio-numerical) — Applied Computational Fluid Dynamics, chapter 4