Casio F-91W: The World's Most Familiar Digital Watch

The Casio F-91W may be the most widely worn watch on Earth. Introduced in 1989 and still in production, this inexpensive resin digital watch is widely reported to be one of the best-selling watches ever made, and its design has barely changed in more than three decades.

Origins

The F-91W was introduced in June 1989 as the successor to the F-87W. It was designed by Ryūsuke Moriai , and it was his first design for Casio. Its trapezoidal resin case, black face and gold-and-blue printed legends became one of the most recognisable watch designs of the late twentieth century.

Specifications

The case measures 37.5 × 33.5 × 8.5mm and the watch weighs just 21 grams . A single CR2016 lithium cell is rated for about seven years , and because owners rarely use the light and alarm heavily, batteries often last longer. Functions include the time and date, a daily alarm, an hourly chime, a stopwatch and a small side-mounted light. Despite the "Water Resist" printing, it is designed for splashes and rain rather than swimming.

Why It Endures

The F-91W succeeds because it does almost nothing wrong: it is light, accurate, legible, cheap and unbreakable in everyday use. It has become a design classic and a fixture in museum collections and pop culture, worn by everyone from schoolchildren to celebrities. Its simplicity has also made it a favourite for hobbyist modification, from replacement straps and cases to replacement circuit boards.

F-91W vs. Other Casio Classics

Buyers wanting more functions at a similar price often look at the AE-1200 "Casio Royale", which adds world time and a 10-year battery, or the CA-53W calculator watch. For the toughest Casio digital, the square G-Shock DW-5600 is the step up. For the 1980s digital rival from America, see the Timex Ironman.

Frequently Asked Questions

When was the Casio F-91W released?
In June 1989, as the successor to the Casio F-87W.

Who designed the F-91W?
Ryūsuke Moriai, in his first design for Casio.

How long does the F-91W battery last?
Casio rates its CR2016 battery for about seven years, and it often lasts longer with light use.

Is the F-91W waterproof?
It is splash-resistant only; it is not designed for swimming or diving.

How big is the F-91W?
37.5 x 33.5 x 8.5mm, weighing about 21 grams.

Related Reading

• Casio: Brand History
• Casio AE-1200 'Casio Royale'
• Casio Calculator Watches