---
title: "File size: 20 s, 44.1 KHz, 8-bit stereo"
subject: "Multimedia System"
chapter: 2
key: "semester_8/multimedia_system:audio-size-20s-44khz-8bit"
source: https://www.bctengineer.com/q/semester_8/multimedia_system/audio-size-20s-44khz-8bit
site: BCT Engineering
---

# File size: 20 s, 44.1 KHz, 8-bit stereo

Multimedia System · Chapter 2: Sound / Audio System

- Asked in: 2072 Magh, 5 marks
- Video: [How to Calculate Audio File Size - Multimedia Numerical](https://www.youtube.com/watch?v=BRzAV1wgyNM) — Simple Snippets
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_8/multimedia_system/audio-size-20s-44khz-8bit
- Whole chapter: https://www.bctengineer.com/md/semester_8/multimedia_system/chapter-2

## Question

Calculate the file size if we record the 20 second of stereo music at 44.1 KHz with 8 bits.

## Short answer

Multiply 44,100 by 8 bits by 2 channels by 20 seconds, divide by 8: 1,764,000 bytes (about 1.68 MB).

## Answer

The size of an uncompressed (PCM) audio file is found from the sampling rate, the resolution, the number of channels and the duration.

**File size (bytes) = sampling rate x bits per sample x channels x time / 8**

#### Given

- Sampling rate = 44.1 kHz = 44,100 samples per second
- Resolution = 8 bits per sample = 1 byte
- Channels = 2 (stereo)
- Time = 20 seconds

#### Calculation

1. Samples per second for both channels = 44,100 x 2 = 88,200
2. Bits per second = 88,200 x 8 = 705,600 bits/s
3. Bytes per second = 705,600 / 8 = 88,200 bytes/s
4. Total size = 88,200 x 20 = **1,764,000 bytes**

#### In larger units

- 1,764,000 / 1024 = 1,722.66 KB
- 1,764,000 / (1024 x 1024) = 1.68 MB

Check in one line: 44,100 x 8 x 2 x 20 / 8 = 1,764,000 bytes.

The file size is **1,764,000 bytes** (about 1.68 MB). A WAV file would also have a small header (about 44 bytes), which is ignored here.

## Check yourself

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

1. Which formula gives the size of this recording?
   A. 44,100 x 8 x 20
   B. 44,100 x 8 x 2 x 20
   C. 44,100 x 8 x 2 x 20 / 8
   D. 44,100 x 2 x 20 x 8 x 8
   Answer: C. Size = rate x bits x channels x time / 8, so bits are converted to bytes. (Key point: Formula)

2. At 44.1 KHz, 8-bit stereo, how many bytes per second are produced?
   A. 88,200
   B. 44,100
   C. 176,400
   D. 705,600
   Answer: A. 44,100 samples x 2 channels x 1 byte = 88,200 bytes/s. (Key point: Bytes per second)

3. What is the file size of 20 seconds at 44.1 KHz, 8-bit, stereo?
   A. 882,000 bytes
   B. 3,528,000 bytes
   C. 1,764,000 bytes
   D. 14,112,000 bytes
   Answer: C. 88,200 x 20 = 1,764,000 bytes (about 1.68 MB). (Key point: Final size)

## Close variants set in other exams

- [File size: 10 s, 44.1 KHz, 16-bit stereo](https://www.bctengineer.com/question.md?key=semester_8%2Fmultimedia_system%3Aaudio-size-10s-44khz-16bit) — Multimedia System, chapter 2, asked 2×

## Related in Multimedia System

- [File size: 20 s, 44.1 KHz, 16-bit stereo](https://www.bctengineer.com/question.md?key=semester_8%2Fmultimedia_system%3Aaudio-size-20s-44khz-16bit) — Multimedia System, chapter 2, asked 3×
- [File size: 60 s, 44.1 KHz, 8-bit stereo](https://www.bctengineer.com/question.md?key=semester_8%2Fmultimedia_system%3Aaudio-size-60s-44khz-8bit) — Multimedia System, chapter 2, asked 3×
- [File size: 30 s, 44.1 KHz, 8-bit stereo](https://www.bctengineer.com/question.md?key=semester_8%2Fmultimedia_system%3Aaudio-size-30s-44khz-8bit) — Multimedia System, chapter 2, asked 3×