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

binary64

The 64-bit IEEE format, used for C++ double - 1 sign bit, 11 exponent bits, 52 fraction bits.

binary64 has a 1-bit sign, an 11-bit biased exponent (bias 1023) and a 52-bit fraction, giving 53 significant bits (about 15 to 17 decimal digits) and a largest finite value near 1.8 * 10^308.

Examples

  • 1.0 as a double is 0x3FF0000000000000.

See also

exponent field exponent bias fraction field significand
Read the full section →