Head-to-Head Comparison

Updated September 5, 2026

Casio MRW-230H vs Rolex Milgauss 40

Two timepieces compared — Under $50 vs $10,000–$25,000

Quick Verdict

The Casio MRW-230H (Under $50) offers Casio Quartz (Battery) precision in the tier below the Rolex Milgauss 40 ($10,000–$25,000). The MRW-230H measures 44.6mm (47.9 x 44.6 x 12.3mm) and is rated 100m (10 ATM). The Milgauss 40 counters with Swiss Made craftsmanship and 100m (10 ATM) water resistance. Both are exceptional timepieces for their respective tiers.

CasioMRW-230HUnder $50 Check price RolexMilgauss 40$10,000–$25,000 Check price

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Casio

MRW-230H

Under $50

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Rolex

Milgauss 40

$10,000–$25,000

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Specifications Compared

Feature	Casio MRW-230H	Rolex Milgauss 40
Price	Under $50	$10,000–$25,000
Case Size	44.6mm (47.9 x 44.6 x 12.3mm)	40mm
Movement	Quartz	Automatic Caliber 3131
Caliber Type	Casio Quartz (Battery)	Rolex In-House Automatic with Parachrom hairspring, Superlative Chronometer
Power Reserve	Approx. 3-year battery (SR626SW)	About 48 hours
Water Resistance	100m (10 ATM)	100m (10 ATM)
Crystal	Resin Glass	Sapphire Crystal (clear on 116400, green-tinted on 116400GV)
Case Material	Resin case, aluminum bezel ring	Oystersteel
Origin	Casio (Japan)	Swiss Made

Category-by-Category Analysis

🎨

Design & Aesthetics

Edge: Draw

Casio's design language vs Rolex's approach

The Casio MRW-230H features a Resin case, aluminum bezel ring case at 44.6mm (47.9 x 44.6 x 12.3mm) with Resin Glass protection. The Rolex Milgauss 40 offers Oystersteel construction at 40mm with Sapphire Crystal (clear on 116400, green-tinted on 116400GV). Both represent their brand's distinct design philosophy and heritage.

⚙️

Movement & Performance

Edge: Rolex

Quartz vs Automatic Caliber 3131

The MRW-230H runs the Quartz (Casio Quartz (Battery), Approx. 3-year battery (SR626SW) power reserve) at standard frequency. The Milgauss 40 uses the Automatic Caliber 3131 (Rolex In-House Automatic with Parachrom hairspring, Superlative Chronometer, About 48 hours reserve) at standard. The Milgauss 40 offers a longer power reserve.

📏

Wearability & Fit

Edge: Rolex

44.6mm (47.9 x 44.6 x 12.3mm) vs 40mm — different wrist presence

At 44.6mm (47.9 x 44.6 x 12.3mm), the MRW-230H has a bolder wrist presence compared to the Milgauss 40 at 40mm. Water resistance differs: 100m (10 ATM) vs 100m (10 ATM).

💰

Value & Cost of Ownership

Edge: Casio

Casio sits in the lower tier

The Casio MRW-230H sits at Under $50 and the Rolex Milgauss 40 at $10,000–$25,000. On the specs that outlast any price: the MRW-230H uses Resin Glass with Approx. 3-year battery (SR626SW), against Sapphire Crystal (clear on 116400, green-tinted on 116400GV) and About 48 hours on the Milgauss 40. Service intervals are typically 5-7 years for both.

💧

Water Resistance

Edge: Draw

100m (10 ATM) vs 100m (10 ATM)

The MRW-230H is rated to 100m (10 ATM) while the Milgauss 40 handles 100m (10 ATM). Both offer identical water resistance ratings.

Our Verdict

Casio

MRW-230H

Choose the Casio MRW-230H if you prioritize Casio Quartz (Battery) engineering, Casio (Japan) craftsmanship, and 100m (10 ATM) water resistance. At Under $50, it delivers Quartz with Approx. 3-year battery (SR626SW) power reserve.

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Rolex

Milgauss 40

Choose the Rolex Milgauss 40 if you value Rolex In-House Automatic with Parachrom hairspring, Superlative Chronometer technology, Swiss Made heritage, and 40mm proportions. At $10,000–$25,000, the Automatic Caliber 3131 with About 48 hours power reserve makes it a compelling choice.

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The Bottom Line

The Casio MRW-230H and Rolex Milgauss 40 represent two distinct approaches to the timepiece category — the Casio bringing Casio (Japan) tradition while Rolex delivers Swiss Made engineering.

Frequently Asked Questions

The Rolex Milgauss 40 is the better buy if you want a mechanical movement; the Casio MRW-230H is the better buy if you want quartz accuracy with no servicing. On price, the Casio MRW-230H sits a band lower (Under $50 against $10,000–$25,000), 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 MRW-230H offers better upfront value, sitting a tier lower at Under $50. However, the Rolex Milgauss 40 may justify its premium with superior finishing, heritage, or resale value.

Both are suitable for daily wear. The MRW-230H at 44.6mm (47.9 x 44.6 x 12.3mm) with 100m (10 ATM) water resistance handles everyday situations. The Milgauss 40 at 40mm with 100m (10 ATM) is similarly capable. The MRW-230H uses Resin Glass while the Milgauss 40 uses Sapphire Crystal (clear on 116400, green-tinted on 116400GV).

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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.