A standard ASCII character is encoded using 7 bits.

Quick Scoop

  • The original ASCII encoding scheme was designed as a 7-bit code, giving 27=1282^7=12827=128 possible character values (from 0 to 127).
  • These 128 codes cover control characters, digits, uppercase and lowercase English letters, punctuation, and a few symbols.
  • In modern computers, characters are usually stored in an 8-bit byte, but for plain ASCII the extra (8th) bit is simply unused or set to 0, so the encoding definition itself is still 7 bits per character.

So, according to the ASCII encoding scheme, 7 bits are used to encode a character.

TL;DR: ASCII defines 7 bits per character; hardware typically stores it in an 8‑bit byte, but the scheme itself is 7-bit.