Casio F-91W
Often described as the best-selling watch model ever made: 35 mm resin case, acrylic crystal, splash resistance (Casio publishes no meter rating), microlight, stopwatch, alarm and a seven-year battery. In production since 1989.
In stock · sold by Amazon.com. Price as of November 3, 2026, 18:15 UTC.
2 versions of the Casio F-91W
Same case and movement, different dial, bezel or strap. Each line is its own Amazon listing with its own price today; the strap variants earn fewer spec points than the bracelet.
| Reference | Dial / strap | Strap | Spec pts | Price | Value Score | Sales rank | Buy |
|---|---|---|---|---|---|---|---|
F-91W-1 Best value | Black resin | Resin | 29 | $18.95 | 88 | #1 | Amazon |
 F-91WM-3A | Green resin, metallic face | Resin | 29 | $21.92 | 82 | #1 | Amazon |
Amazon.com prices as of November 3, 2026, 18:15 UTC — details.
Will the Casio F-91W fit your wrist?
Enter your wrist circumference. The drawing scales the case (35.2 mm across, 38.2 mm lug-to-lug) against the flat top of a wrist that size, using the 3.6× lug-to-lug rule from our fit guide. Needs JavaScript; the rule itself is on the fit guide.
What you get
Published manufacturer specifications. Fields we could not verify are left out rather than guessed.
How the 29 spec points add up
Value Score = 100 × √(spec points per dollar ÷ the best ratio among basic digital watches in stock on Amazon today). Full methodology.
Compared with other basic digital watches
Same type, other model families, verified Amazon prices today. See the full Basic Digital Watches ranking →
| # | Watch | Movement | Crystal | Water res. | Case diameter × lug-to-lug | Fits wrist | Spec pts | Price | Value Score | Buy |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | | Digital quartz | Acrylic | — | 35.2 × 38.2 mm | ≥ 13.8 cm (5.4″) | 29 | $18.95 | 88 | Amazon |
| 2 |  | Digital quartz | Acrylic | 100 m | — | — | 41 | $29.92 | 84 | Amazon |
| 3 |  | Digital quartz | Mineral | 200 m | — | — | 49 | $42.98 | 76 | Amazon |
| 4 |  | Digital quartz | Acrylic | 100 m | 42.1 × 45 mm | ≥ 16.2 cm (6.4″) | 41 | $37.98 | 74 | Amazon |
| 5 |  | Digital quartz | Acrylic | 100 m | — | — | 41 | $39.95 | 72 | Amazon |
| 6 |  | Digital quartz | Acrylic | 100 m | 42.1 × 45 mm | ≥ 16.2 cm (6.4″) | 44 | $48.88 | 68 | Amazon |
| 7 |  | Solar digital | Acrylic | 100 m | — | — | 47 | $53.95 | 67 | Amazon |
Amazon.com prices as of November 3, 2026, 18:15 UTC — details. third-party = sold by a marketplace seller, not Amazon (warranty may differ); ships later = not in stock today, never crowned best value.
Questions about the Casio F-91W
How much does the Casio F-91W cost on Amazon?
What is the Value Score of the Casio F-91W?
What wrist size fits the Casio F-91W?
What are alternatives to the Casio F-91W?
Guides that apply to this watch
- Ranked among watches under $100
- This listing is below its list price today: all watches below list price
- Sapphire vs Hardlex vs mineral: what the crystal changes
- Will it fit your wrist? The lug-to-lug rule
- Automatic vs solar vs quartz: accuracy and running cost
- Watch gift guide by budget and recipient
- Buying a watch on Amazon: sellers, warranty, returns