Casio F-91W
digital watch manufactured by Casio
The Casio F-91W is a digital watch manufactured by Japanese electronics company Casio. Introduced in June 1989 as a successor of the F-87W, it is popular for its low price, long battery life, and iconic design. As of 2026, production of the watch was 100 million, which made it the most sold watch in the world.
Specifications
Design
Designed by Ryūsuke Moriai as his first design for Casio, the case of the F-91W measures 37.5 by 34.5 by 8.5 millimetres (1.48 by 1.36 by 0.33 in). The case is primarily made of resin, with a stainless steel caseback and buttons, with the manufacturer's module number, 593, stamped on the caseback. The resin strap is 18 millimetres (0.71 in) at the fitting and 22 mm across the widest part of the lugs. The total weight is 21 grams (0.74 oz).
Features
The F-91W has a chronograph, featuring precision of 1⁄100 seconds with a count up to 59:59.99 (nearly one hour). The chronograph is also able to mark net and split times (i.e., laps). Other features include an hourly time beep, a single daily alarm lasting 20 seconds and an annual calendar.
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This entry incorporates text from “Casio F-91W” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.