OCR GCSE CS · J277
Sound & Images
My Year 11 recap quiz · Data representation
Storage Units (× 1,000)
| Unit | Full name | Value | How to convert |
|---|---|---|---|
| b | bit | 1 bit | — |
| B | byte | 8 bits | bits ÷ 8 → bytes | bytes × 8 → bits |
| KB | kilobyte | 1,000 bytes | bytes ÷ 1,000 → KB | KB × 1,000 → bytes |
| MB | megabyte | 1,000 KB | KB ÷ 1,000 → MB | MB × 1,000 → KB |
| GB | gigabyte | 1,000 MB | MB ÷ 1,000 → GB | GB × 1,000 → MB |
| TB | terabyte | 1,000 GB | GB ÷ 1,000 → TB | TB × 1,000 → GB |
Key Formulae
Image size (bits)
width (px) × height (px) × colour depth (bits)
Image size (bytes)
width × height × colour depth ÷ 8
Sound size (bits)
sample rate (Hz) × bit depth × duration (s)
Sound size (bytes)
sample rate × bit depth × duration ÷ 8
Stereo sound
multiply final size × 2 (two channels)
Colours available
2 ^ colour depth
Data rate
sample rate × bit depth (bits per second)