Sound File-Size Calculations — Text, Sound and Images | IGCSE Computer Science

Exam Frequency Analysis

Past paper frequency (2018 to 2024)

This topic accounts for approximately 5% of your exam marks.

stable

Rare

Stable5%

ASCII/Unicode, sound sampling and pixel/colour depth appear regularly as 2 to 4 mark questions.

The standard exam formula for the size of an uncompressed sound file is:

file size (bits) = × × duration

where:

sample rate is in hertz (samples per second)
sample resolution is in bits per sample
duration is in seconds

To convert to bytes, divide by 8 (since 1 byte = 8 bits). To convert to kilobytes, divide by 8000 (or 8192 if the question uses the binary definition of a kilobyte).