Skip to content
Free public beta until December 4, 2026: every course is open, no card needed. After that, the first chapter of each course stays free and full access is a one-time $39 ($19 for up to 100 founding members chosen for helpful feedback). Your progress is kept. How the beta works

sign bit

The top bit of a signed number, which is 1 when the number is negative.

In an n-bit signed representation the most significant bit, bit n-1, indicates the sign; in two's complement it carries the weight -2^(n-1).

Examples

  • The 8-bit pattern 10000001 has sign bit 1, so read as signed it is negative: −127.

See also

sign-magnitude two's complement sign extension
Read the full section →