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GCSE Computer Science/Paper 1/Data Storage: Characters

Calculate file sizes of text

1.2.4b Data Storage: Characters

Practise exam questions

Data Storage: Characters — Note 1 of 4

What you need to know

The file size of a text file can be calculated using the formula: text file size = bits per character × number of characters. You may need to convert the result between units (bits, bytes, KB, etc.).

What to know

  • Text file size = bits per character × number of characters.
  • Remember to count ALL characters including spaces and punctuation.
  • To convert bits to bytes, divide by 8.
  • Example: 'Hello World' encoded in ASCII (8 bits per character) = 11 characters × 8 bits = 88 bits = 11 bytes.

Exam technique

  • Tip:Check carefully whether the question gives bits per character or bytes per character — this affects your calculation.

Ready to test yourself?

Practise 1.2.4b questions
← Previous topicBinary shifts1.2.4a Data Storage: NumbersNext note →The use of binary codes to represent characters1.2.4b Data Storage: Characters

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Revise another OCR GCSE topic: Data Storage: Numbers

Data Storage: Characters

Note 1 of 4

  1. 1Calculate file sizes of text
  2. 2The use of binary codes to represent characters
  3. 3The term 'character set'
  4. 4The relationship between the number of bits per character in a character set, and the number of characters which can be represented, e.g. ASCII, Unicode
Topic overview

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