Official FIDE Rating List

The Official FIDE Rating List is the publication that establishes the numbers recognized by FIDE, the International Chess Federation. A rating is a number that estimates playing strength from rated results. The list is prepared on the first day of each month and incorporates play rated during the period attached to the preceding list.

A rating period is the interval during which a particular list is valid and results are gathered for an update. The new list replaces the previous one as the administrative reference. An event received after the processing deadline may appear in a later publication.

The official number should not be confused with a live rating. A live calculation tries to anticipate the effect of recent games, but it can change because of corrections, reporting dates, or processing rules. The FIDE database also separates standard, rapid, and blitz categories, so each number must be read in its own format.