Smartwatches have too many features, and luxury watches make me worry…
If that sounds like you, there is a watch that strikes a remarkably good balance.
The CASIO F-91W is the world's best-selling watch.
It is light, readable, and popular around the world.
The World's Leading Watch
Priced in the 1,000-yen range, with only the essential features, yet still selling after more than 30 years—
its name is CASIO F-91W.
At first glance, it is an unassuming digital watch.
Yet minimalists, soldiers, politicians, enthusiasts, and meme fans around the world love this watch as a legend.
The F-91W series is a long-running bestseller with more than 100 million watches sold worldwide
Why does the F-91W still hold such a prominent place in the watch world?
Here are the reasons behind its formidable reputation in detail.
Why the F-91W Is Called the World's Best
Extraordinary Sales and a Long-Running Record
- Released in 1989
- More than 3 million continue to sell each year—an extraordinary figure
- It is also described as the world's most widely worn wristwatch
5 Reasons to Buy an F-91W
- Exceptional value: 1,500 yen for 7 years of use
- So light that it does not tire your wrist: 21g
- Water resistance(30m water resistance for everyday use)
- A battery life of 7 years
- Retro yet practical; inexpensive enough not to worry about damage; a conversation starter
Where to Buy the Casio F-91W-1
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Where to Buy a Screen Protector for Casio F-91W
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Remarkable Value for Money
- List price: 2,200 yen
- Battery life: approximately 7 years
- Lightweight resin construction, just 21g
- Everyday water resistance, an alarm, and a stopwatch
Versatility That Appeals to All Kinds of People
- A child's first watch
- A minimalist's only watch
- A practical tool for soldiers or workers
- A deliberately unexpected fashion choice
Stories That Shook the World? The Legends of the Casio F-91W
People around the world keep searching for the F-91W as a legendary watch because its exceptional practicality and low price have generated historical anecdotes reaching from the criminal underworld to space.
✅ A Model Worn by Osama bin Laden
It is known for having been worn publicly by Osama bin Laden, the former leader of the Islamist extremist organization al-Qaeda, and overseas it is sometimes called the bin Laden model.
✅ A History of Misuse in Timed Explosive Devices
Available almost anywhere for a few hundred yen, exceptionally resistant to damage, and with an unusually accurate stopwatch
—for those reasons, terrorist organizations misused it extensively as a timer in improvised explosive devices, or IEDs.
One disturbing story holds that CIA documents relating to the Guantanamo Bay military base listed possession of an F-91W as one criterion for identifying a terrorist.
✅ Record-Book-Level Toughness: A Return After 20 Years
In 2015, a British man found an F-91W in his garden that he had lost 20 years earlier。
The light had failed, but the watch itself was still running normally and was only 7 minutes slow.
CASIO's public-relations team reportedly acknowledged that it could happen under the right conditions—making its accuracy and durability seem truly legendary.
✅ Is the F-91W NASA's Official Watch?
Online, stories sometimes claim that NASA astronauts used the F-91W. More precisely, however, the watches officially approved by NASA and used in space were its G-SHOCK relatives, such as models in the DW-5600 series.
Still, the fact that watch fans worldwide seriously debate whether an F-91W could go to space says much about the potential they see in it.
More Reasons People Love the F-91W
✅ Celebrities and the F-91W: Former President Obama Wore One, Too!
It briefly went viral after former President Barack Obama was seen wearing one, and it also has many fans among well-known DJs and rappers.
✅ An F-91W Loved on the Battlefield
- Worn by soldiers in Afghanistan and Iraq
- Listed in CIA documents as a model favored by members of terrorist organizations
- Even described as a watch used to identify targets
✅ The F-91W's Popularity as an Internet Meme
Holding down the bottom-right button on the time display brings up the letters CASIO is a widely known hidden trick around the world.
What Makes the F-91W So Appealing
Remarkably Light: The Comfort of 21g
- At 21g, its body is so light you forget you are wearing it
- While exercising, working, or sleeping, it stays unobtrusive
Repairs and Modifications Anyone Can Try
- You can open the case back and replace the battery yourself
- Custom dials and band swaps are popular too
- The fun of becoming a custom F-91W craftsperson, wherever you live
An Appeal You Do Not Get With Analog Watches
- Easy readability that an analog display does not provide
- A rugged, cool digital display
- A practical stopwatch and alarm
- Its retro-digital, deliberately digital character has an appeal of its own
An Honest Look at the F-91W's Shortcomings
A Weak Light: Is That an Outdated Complaint?
Older F-91Ws used a small green bulb with limited brightness.
Many people said it was dark and difficult to read.
However, recent production batches have been improved with LED lighting and it is brighter and easier to read than before.
Even so, it is still a small point light rather than a full backlight and visibility remains imperfect.
*Some watches still in circulation may retain the older specification, so check before buying.
Some People Find It Cheap-Looking
- The resin case does not have a luxury feel
- Many fans, however, see that rugged simplicity as part of its character
Water Resistance Is Basic
- For everyday use, such as rain and handwashing
- Swimming and bathing are considered unsuitable, although it will generally cope
Popular Inexpensive Casios Often Compared With the F-91W
How It Differs From the A158W
→ A related design with a metal finish.If you prefer a metal band and prioritize the feel of the materials, consider this model.
Where to Buy the Casio A158WA-1
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The A158WEA-9 with a gold dial is a nice option too.
Where to Buy the Casio A-158WEA-9
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How It Differs From the F-105W
→ Larger and easy to read, with a full-display backlight for dark conditions.Choose the F-105W for an EL Backlight That Works Well at Night
Where to Buy the Casio F-105W-1AW
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How the F-91W Differs From Other Inexpensive Casios
The F-91W stands out for its light weight, durability, and history.
F-91W Reviews: What Owners Think
「light, inexpensive, and durable are the 3 qualities that receive overwhelming support.
Across owner comments and specialist publications, comfort on the wrist at 21g、practicality beyond its price、better-than-expected accuracy are frequent themes.
On the other hand, weak lighting、basic everyday water resistance、the lifespan of the resin band are cited as weaknesses.British GQ+2Hodinkee+2
- Exceptionally light and thin: some even describe it as uber-light and thin.
Many say it remains comfortable over long periods.Hodinkee - Plenty of features for the price: international publications have described it as exceptional value—best bang for your buck.British GQ
- High accuracy: some measured results are within a few seconds per month (the published specification is ±30 seconds per month).
Owners do not need to adjust the time frequently in everyday use.watchguy.co.uk+1 - Cultural and fashion appeal: celebrity sightings and descriptions of it as an inexpensive but knowledgeable choice appear too.
Financial Times +1
- The light, or Microlight, is relatively weak: in the dark, the assessment is readable, but not ideal.Wikipedia
- Water resistance is for everyday use, at 3 atmospheres：Swimming and bathing are not recommended。
Community members report success, but it is outside the official specification and is not recommended.Wikipedia +1 - the lifespan of the resin band：Sweat and ultraviolet exposure can cause it after 1 to a few years to start cracking.
Many people switch to NATO-style or nylon bands and keep using the watch.Reddit+1
- 「Objectively, the F-91W is the best. The battery lasts 7–10 years, and it is exceptionally comfortable. (Owner post)Reddit
- 「A classic under 20 dollars that works with both a school uniform and a suit. (Media review)British GQ
- 「Inexpensive, light, simple, and reliable—no unnecessary features. (Column)Financial Times
- High ratings numbering in the tens of thousands on Amazon and other retailers: as of 2024, over 60,000 reviews, averaging 4.6/5 was reported, and it remained a bestseller in 2025.El País
- Specialist publications also continue to cover it as a staple in the 15–20-dollar range.Hodinkee
- For low-light readability: if nighttime use matters, the F-105W with a full EL backlight is worth considering too.
- For band longevity：switching to a thin 18mm NATO-style or nylon band can improve comfort and longevity.
Community guides can help with the replacement process.
Where to Buy an Airself 18mm NATO-Style Nylon Watch Band
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Video Guide: The F-91W Legend
My Take: The F-91W Is a Leading Watch With Stories to Tell
Inexpensive, light, and durable.
More than 30 years of history, with stories that are still being told.
The F-91W is loved worldwide as a culture or philosophy that goes beyond being just a wristwatch.
The F-91W is a complete watch, balancing features, price, and history.
In a very different way from luxury watches, it could fairly be called the wristwatch with the most stories to tell.
Experience that legendary appeal on your own wrist.
Where to Buy the Casio F-91W-1
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Where to Buy a Screen Protector for Casio F-91W
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Specifications
| Model | F-91W |
| Size (L × W × H) | 38.2 × 35.2 ×8.5 mm |
| Weight | 21g |
| Band Material | Urethane |
| Bezel Material | Urethane |
| Features | Water resistance for everyday use |
*For reference
The F-91W replacement battery is a CR2016.
Where to Buy Panasonic CR2016 3V Lithium Coin Batteries (5-Pack)
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