IEEE 754-1985 governs binary floating-point arithmetic. It specifies number formats, basic operations, conversions, and exceptional conditions. The related standard IEEE 854-1987 generalizes 754 to cover decimal arithmetic as well as binary.

Note that materials provided on this page and sub-pages are not approved as IEEE standards. The two current, approved standards are 754-1985 and 854-1987. The materials provided through this page are purely informative.

Revision

The standard is undergoing revision. Participation is open to people with a solid knowledge of floating-point arithmetic. We hold monthly meetings in the San Francisco Bay area. The mailing list tracks running discussions.

Reading Material

Some answers to frequently asked questions are available. A large amount of material, online and dead-tree, has accumulated over the years. The earlier publications provide rationale for the current standard, IEEE 754-1985.

Good, on-line works include the following:

• David Goldberg's article, What Every Computer Scientist Should Know about Floating-Point Arithmetic, covers important aspects of floating-point arithmetic from the perspective of IEEE 754. Doug Priest's supplement describes many 754 implementations.
• Lecture Notes on the Status of IEEE Standard 754 for Binary Floating-Point Arithmetic by Prof. W. Kahan provides a tour of some under-appreciated features of IEEE 754 and includes many examples where they clarify numerical algorithms.
• Lefèvre and Muller's work on the table-maker's dilemma outlines the difficulties in specifying elementary functions.
• David Bindel has collected an annotated bibliography that lists many relevant works.