---
title: "File size: 20 s, 44.1 KHz, 16-bit stereo"
subject: "Multimedia System"
chapter: 2
key: "semester_8/multimedia_system:audio-size-20s-44khz-16bit"
source: https://www.bctengineer.com/q/semester_8/multimedia_system/audio-size-20s-44khz-16bit
site: BCT Engineering
---

# File size: 20 s, 44.1 KHz, 16-bit stereo

Multimedia System · Chapter 2: Sound / Audio System

- Asked in: 2073 Bhadra, 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-16bit
- Whole chapter: https://www.bctengineer.com/md/semester_8/multimedia_system/chapter-2

## Question

Calculate the file size in bytes for a 20 second recording at 44.1 KHz, 16 bits resolution stereo sound.

## Short answer

Multiply sampling rate 44,100 by 16 bits by 2 channels by 20 seconds, divide by 8: 3,528,000 bytes (about 3.36 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 = 16 bits per sample = 2 bytes
- 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 16 = 1,411,200 bits/s
3. Bytes per second = 1,411,200 / 8 = 176,400 bytes/s
4. Total size = 176,400 x 20 = **3,528,000 bytes**

#### In larger units

- 3,528,000 / 1024 = 3,445.31 KB
- 3,528,000 / (1024 x 1024) = 3.36 MB

Check in one line: 44,100 x 16 x 2 x 20 / 8 = 3,528,000 bytes.

The file size is **3,528,000 bytes** (about 3.36 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. How many bytes does one 16-bit sample take?
   A. 1
   B. 16
   C. 4
   D. 2
   Answer: D. 16 bits / 8 = 2 bytes per sample. (Key point: Bytes per sample)

2. For 44.1 KHz, 16-bit stereo, what is the data rate in bytes per second?
   A. 176,400
   B. 88,200
   C. 1,411,200
   D. 352,800
   Answer: A. 44,100 x 2 x 16 = 1,411,200 bits/s, which is 176,400 bytes/s. (Key point: Bytes per second)

3. What is the file size of 20 seconds at 44.1 KHz, 16-bit, stereo?
   A. 1,764,000 bytes
   B. 3,528,000 bytes
   C. 7,056,000 bytes
   D. 28,224,000 bytes
   Answer: B. 176,400 bytes/s x 20 s = 3,528,000 bytes (about 3.36 MB). (Key point: Final size)

## Close variants set in other exams

- [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×

## Related in Multimedia System

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