Head-to-Head Comparison

Updated September 5, 2026

Casio F-91W vs Hamilton Khaki Field Automatic

Casio's timepiece meets Hamilton's field watch

Quick Verdict

The Casio F-91W (Under $50) offers Casio Digital Quartz (Battery) precision in the tier below the Hamilton Khaki Field Automatic ($500–$1,000). The F-91W measures 35mm and is rated 30m (Splash Resistant). The Khaki Field Automatic counters with Swiss Made craftsmanship and 100m (10 ATM) water resistance. Both are exceptional watches for their respective tiers.

CasioF-91WUnder $50 Check price HamiltonKhaki Field Automatic$500–$1,000 Check price

Transparency — We earn a small commission on purchases made through our Amazon links. This doesn't affect our editorial independence.

Casio

F-91W

Under $50

Check Price Full Review

Hamilton

Khaki Field Automatic

$500–$1,000

Check Price Full Review

Specifications Compared

Feature	Casio F-91W	Hamilton Khaki Field Automatic
Price	Under $50	$500–$1,000
Case Size	35mm	38mm
Movement	Quartz Module 593	Automatic H-10
Caliber Type	Casio Digital Quartz (Battery)	Automatic (ETA C07.611 base)
Power Reserve	7-Year Battery	80 Hours
Water Resistance	30m (Splash Resistant)	100m (10 ATM)
Crystal	Acrylic	Sapphire Crystal
Case Material	Resin	Stainless Steel
Origin	Casio (Japan)	Swiss Made

Category-by-Category Analysis

🎨

Design & Aesthetics

Edge: Draw

Casio's design language vs Hamilton's approach

The Casio F-91W features a Resin case at 35mm with Acrylic protection. The Hamilton Khaki Field Automatic offers Stainless Steel construction at 38mm with Sapphire Crystal. Both represent their brand's distinct design philosophy and heritage.

⚙️

Movement & Performance

Edge: Hamilton

Quartz Module 593 vs Automatic H-10

The F-91W runs the Quartz Module 593 (Casio Digital Quartz (Battery), 7-Year Battery power reserve) at standard frequency. The Khaki Field Automatic uses the Automatic H-10 (Automatic (ETA C07.611 base), 80 Hours reserve) at 21,600 vph (3 Hz). The Khaki Field Automatic offers a longer power reserve.

📏

Wearability & Fit

Edge: Casio

35mm vs 38mm — different wrist presence

At 35mm, the F-91W wears more compactly on smaller wrists compared to the Khaki Field Automatic at 38mm. Water resistance differs: 30m (Splash Resistant) vs 100m (10 ATM).

💰

Value & Cost of Ownership

Edge: Casio

Casio sits in the lower tier

The Casio F-91W sits at Under $50 and the Hamilton Khaki Field Automatic at $500–$1,000. On the specs that outlast any price: the F-91W uses Acrylic with 7-Year Battery, against Sapphire Crystal and 80 Hours on the Khaki Field Automatic. Service intervals are typically 5-7 years for both.

💧

Water Resistance

Edge: Hamilton

30m (Splash Resistant) vs 100m (10 ATM)

The F-91W is rated to 30m (Splash Resistant) while the Khaki Field Automatic handles 100m (10 ATM). The Khaki Field Automatic offers superior water resistance.

Our Verdict

Casio

F-91W

Choose the Casio F-91W if you prioritize Casio Digital Quartz (Battery) engineering, Casio (Japan) craftsmanship, and 30m (Splash Resistant) water resistance. At Under $50, it delivers Quartz Module 593 with 7-Year Battery power reserve.

Check Price on Amazon

Hamilton

Khaki Field Automatic

Choose the Hamilton Khaki Field Automatic if you value Automatic (ETA C07.611 base) technology, Swiss Made heritage, and 38mm proportions. At $500–$1,000, the Automatic H-10 with 80 Hours power reserve makes it a compelling choice.

Check Price on Amazon

Try Prime Free — Free Shipping on Both Watches Students & 18–24: start Prime for Young Adults free

The Bottom Line

The Casio F-91W and Hamilton Khaki Field Automatic represent two distinct approaches to fine watchmaking — the Casio bringing Casio (Japan) tradition while Hamilton delivers Swiss Made engineering.

Frequently Asked Questions

The Hamilton Khaki Field Automatic is the better buy if you want a mechanical movement; the Casio F-91W is the better buy if you want quartz accuracy with no servicing. For water, the Hamilton Khaki Field Automatic is rated 100 m against 30 m, which is the difference between swimming and diving on one side and splashes on the other. On price, the Casio F-91W sits a band lower (Under $50 against $500–$1,000), so it is the cheaper way into the category. Neither is better at everything; the spec table above shows movement, case size, water resistance and crystal side by side so you can weigh what matters to you. We do not test units, so this is the makers' data, not a bench result.

The Casio F-91W offers better upfront value, sitting a tier lower at Under $50. However, the Hamilton Khaki Field Automatic may justify its premium with superior finishing, heritage, or resale value.

Both are suitable for daily wear. The F-91W at 35mm with 30m (Splash Resistant) water resistance handles everyday situations. The Khaki Field Automatic at 38mm with 100m (10 ATM) is similarly capable. The F-91W uses Acrylic while the Khaki Field Automatic uses Sapphire Crystal. Sapphire resists scratches noticeably better than acrylic.

More Comparisons

Tissot PRX vs Hamilton Khaki Field

Integrated bracelet sophistication meets military heritage

Hamilton Khaki Field Automatic vs Seiko 5 Sports

Same 100m rating, roughly triple the price

Hamilton Khaki Field Auto vs Longines HydroConquest

Swiss field watch or Swiss dive watch

Explore These Watches

Casio F-91W — Full Review Hamilton Khaki Field Automatic — Full Review Browse All Guides

How This Page Was Made

Our comparisons are generated from a hand-maintained specification database and reviewed under our editorial standards. We use AI tools to assemble pages from that data. We don’t invent specs: every number traces back to the database, and when we correct an entry, the fix is applied site-wide. As an Amazon Associate, The Horologist earns from qualifying purchases.