Casio F-91W Full Review


Casio standing up on plaid

Jack Baruth clued me in to the Casio F-91W. “Most luxury watches can’t match an eleven-dollar Taliban graduation watch for accuracy,” Jack wrote. Sure enough, Wikipedia’s Casio F-91W entry has a subsection entitled Usage In Terrorism, cataloging the model’s popularity as an improvised explosive timer and ubiquity among terror detainees . . .

Scouring the Amazon reviews reveals the Casio F-91W is a favorite of military recruits everywhere; it’s an affordable watch that meets the rigors of basic training or dies trying. Tradesmen like them for the same make-or-break odds. Most people buy them because they are inexpensive to the point of disposability.

Casio F-91W and MAG-LITE

The Casio F-91W elicits 1980’s nostalgia despite sharing its end-of-decade birthyear with Taylor Swift. I could’ve sworn I had a Radio Shack F-19W knockoff circa 1986. But no – the basic digital watch had already been standardized to utter homogeneity by then. How do I even remember that far back? Why is this type of watch so memorable?

I decided to buy a Casio F-91W at Walmart. Like the Timex Easy Reader, the watch is always available. No real or imagined shortages here; the Japanese watchmaker churns out three million pieces per year.

Casio product page

I checked ahead on the website. Searching by model number doesn’t bring up the store item. It’s called “Mens Basic Digital Black Watch” – a perfectly accurate if imprecise description. I suspect Walmart avoids the model number because their $15.88 in-store price isn’t very competitive, even with vendors on their own site.

Casio in package

I found several Casio F-91W’s in paperboard display boxes at the end of a shelf in the jewelry department. Picking up one to see if it was working, I thought I was looking at a clear protective decal with a printed display mockup.

The Casio F-91W’s numbers are surprisingly dark and crisp, viewable from all angles without washout. The background is solid and absent of ghost images from inactive portions.

When the seconds changed before my eyes I realized that my fears of digital legibility were unfounded. Less reassuring: the battery’s death march had begun.

Watch with security tag

It would’ve been the most convenient, painless and immediately gratifying watch purchase I’ve ever made if the F-91W hadn’t set off the store’s alarm. What’s the street value of $15.88 digital watch?

The Casio F-91W is no thing of beauty, but it’s clean, minimalist design has stood the test of time. It’s the embodiment of function over fashion. It’s anti-style, unless you’re going for retro nerd chic.

Casio F-91W on plaid

The Casio’s informative face has three different colors of printed text with blue accents. It’s orderly and cohesive. It helps that most of the characters are nearly microscopic. The info is there, but you might need cheaters.

Luckily, the display is as clear as a Crater Lake, despite being smaller than a postage stamp. Thanks to blocky high contrast digits the date and seconds are legible from an arm’s length glance.

Let there be light

The backlight – which Casio tellingly calls a Micro Light – is a notoriously weak yellow/green LED. You activate it by pressing the button on the left. The light quickly fades to nothing before reaching the right side. If you want the date or seconds at night, you’re SOL.

The watch has all the heft of a Cracker Jack prize. This explains its magical ability to stay in place on your wrist even when the band is worn loosely, lacking the mass necessary or overcome the light grip of the synthetic material. The band is pliable enough and disappears from mind – unless the weather is tropical, at which point the zero breathability factor arises.

Casio F-91W on wrist

The case is essentially a 33mm square. I’m fine with that. The way the case and band visually blend – without an abrupt transition point – should assuage those with size insecurity issues. At only 8.5mm thick, the Casio F-91W is a delightfully slim piece that bevels down at the pusher humps and slides under shirt sleeves without issue.

Casio F-91W on wrist

I had to RTFM on setting the time and date, and most importantly turning off the alarm that sounds at some odd hour until this is done.

I accidentally pushed the single right pusher for the few seconds required to see the Easter egg “CASIo” anti-counterfeiting display. Yes, as with two dollar Chinese plastic Hero fountain pens, there are actually fakes out there, some of which have incorporated this stealth hallmark.

Casio F-91W on wrist

The Casio F-91W’s hourly chime is two quick beeps, enough to be noticed but not annoy. Throughout the week, it continued to coincide exactly with a similar cell phone hourly alert, a cheerful reminder of impeccably accurate timekeeping. There is a stopwatch that is simple enough to use, if you are into timing laps or doing Gibrethian motion studies.

On day one, the Casio F-91W’s velvet matte finish suffered a light scratch. That’s plastic for you, and matte can’t be buffed out. The acrylic crystal has escaped damage so far, but I suspect the watch autopsy reports on this model would reveal the top failure modes to be:

– Battery died and user just bought another F-91W
– Crystal scuffed to hell or violently cracked
– Band tore and user just bought another F-91W
– Repeated showering and/or swimming from people misunderstanding what “water resistant” means

In the name of science, I wore the Casio F-91W in the shower. As expected, it didn’t mind at all. Supposedly Water Resistant is roughly equivalent to a 30m rating, so not really recommended. People do it all the time though, and the abuse is endured long enough to convince them that this is okay – until it dies a couple of months later.

Amazon watch review

Searching for the Casio F-91W on Youtube reveals that the watch can be modded for inverted displays using polarized film, or the display hues changed with colored film.

Unsatisfied with F-91W’s 24 hour display, tacticool-seeking owners knock out the taper pins (no spring bars here) to install a NATO strap. I’m into the charm of a mass-produced commodity, so I’ll hold off on all that.

The Casio F-91W is a proven watch from an established manufacturer, checking plenty of functional boxes. It’s not meant to last forever; it will last long enough to exceed the pain-free price. Repeat buyers abound. Reliable not durable, the F-91W is the ultimate expendable dependable.

Model: Casio F-91W
Price: $15.88 (Walmart)


Case Width: 33mm
Case Material: black plastic
Case Back: stainless steel
Crystal/Lens: flat acrylic
Dial: Digital
Module: Casio 593 digital
Water Resistance: 30m

RATINGS (out of five stars):

Design * * *
Cohesive but functional in the anti-style way loved by fans of retro or nerd chic.

Legibility * * * *
Disgustingly good for a tiny display. Cheap crystal is scratch prone. Get the reading glasses for the function labels. Backlight works, but poorly.

Comfort * * * *
Light, slim, with an easily conforming band. But synthetic is not great for hot weather.

Overall * * * *
The preemie G-SHOCK is overbuilt and over-featured for its bargain price. King of the throwaway watches for three decades and counting.


  1. Had me one back then when I worked for heavy-chemical manufacturing company that made acids as an intermediate for the phosphate fertilizer they manufactured. They burned sulfur to generate heat to power the plant, and the waste gas of sulfur dioxide the made sulfuric acid to dissolve the phosphate out of the feed rock to make phosphoric acid.

    My job back then was to travel into the plant regularly to grab samples for chemical analysis. It was a highly corrosive work environment, to say the least. My cotton clothing had a short lifespan.

    The Casio watch, on the other hand, had the printed lettering stripped off of it in short order. But it still worked even as the acrylic watch ‘crystal’ slowly became clouded over. A bit of plastic polish made it clear enough to be functional for another few months. Did that a few times before I left for a better job and chucked the ‘acid watch’ in the trash…

    • I love it. Such abusive conditions are exactly where this type of watch makes so much sense. There’s no point in subjecting something pricier for the punishment when it’s a guessing game if it will fare any better at all.

      I’m fascinated that the printing came off, as that is on the inside. Maybe they used to be made differently? If anyone wants to see the lengths people go to for a “clean face” or blackout modification:

      Thank you for reading and commenting.

  2. Walmart raised their price on this watch, I don’t think it was 15.88 a few years ago, more like $9.88. Still worth it though. The battery life in these watches is reportedly very good, something like 7 or more years likely depending on how much the backlight ar alarms are used.

    • I don’t know what previous pricing was, but I just checked and the price hasn’t increased since the review.

      These use the same CR2016 cell as the Timex Easy Reader. I think those claim a ten year life (like every G-SHOCK) and I just did the first replacement on mine. That Timex is at least eight years old, and that’s an analog day/date watch with the Indiglo backlight.

      Just yesterday I was watching this video where the F-91W was frozen, boiled, lit on fire, etc. and proved to be ridiculously hearty for such a budget device.

    • I have one bought back in 2006 and it’s still going strong on original battery, beeps are loud and the backlight is glowing as expected. The strap tore after 9 years of use though.

      • It’s obvious that the watch is no energy hog, but it never dawned on me that battery life would be well over the ten year life advertised by lots of Timex watches (mine fell a bit short, but I play with the Indiglo light alot). Then again, it’s the same big flat 2016 cell in them all. These resin straps defy age with me, but I presume one day they start deteriorating quickly. It’s good to hear that not all of these are going to a landfill after a few years.

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