Head-to-Head Comparison

Updated September 5, 2026

Casio MRW-230H vs Rolex Day-Date 18238 (18k yellow gold, blue diamond dial)

Two timepieces compared — Under $50 vs $25,000+

Quick Verdict

The Casio MRW-230H (Under $50) offers Casio Quartz (Battery) precision in the tier below the Rolex Day-Date 18238 (18k yellow gold, blue diamond dial) ($25,000+). The MRW-230H measures 44.6mm (47.9 x 44.6 x 12.3mm) and is rated 100m (10 ATM). The Day-Date 18238 (18k yellow gold, blue diamond dial) counters with Swiss Made craftsmanship and 100m (10 ATM) water resistance. Both are exceptional timepieces for their respective tiers.

CasioMRW-230HUnder $50 Check price RolexDay-Date 18238 (18k yellow gold, blue diamond dial)$25,000+ Check price

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Casio

MRW-230H

Under $50

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Rolex

Day-Date 18238 (18k yellow gold, blue diamond dial)

$25,000+

Check Price Full Review

Specifications Compared

Feature	Casio MRW-230H	Rolex Day-Date 18238 (18k yellow gold, blue diamond dial)
Price	Under $50	$25,000+
Case Size	44.6mm (47.9 x 44.6 x 12.3mm)	36mm
Movement	Quartz	Automatic, Rolex Calibre 3155
Caliber Type	Casio Quartz (Battery)	Rolex 3155, in-house automatic, chronometer
Power Reserve	Approx. 3-year battery (SR626SW)	About 48 hours
Water Resistance	100m (10 ATM)	100m (10 ATM)
Crystal	Resin Glass	Sapphire Crystal, Cyclops
Case Material	Resin case, aluminum bezel ring	18k yellow gold
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 Day-Date 18238 (18k yellow gold, blue diamond dial) offers 18k yellow gold construction at 36mm with Sapphire Crystal, Cyclops. Both represent their brand's distinct design philosophy and heritage.

⚙️

Movement & Performance

Edge: Rolex

Quartz vs Automatic, Rolex Calibre 3155

The MRW-230H runs the Quartz (Casio Quartz (Battery), Approx. 3-year battery (SR626SW) power reserve) at standard frequency. The Day-Date 18238 (18k yellow gold, blue diamond dial) uses the Automatic, Rolex Calibre 3155 (Rolex 3155, in-house automatic, chronometer, About 48 hours reserve) at standard. The Day-Date 18238 (18k yellow gold, blue diamond dial) offers a longer power reserve.

📏

Wearability & Fit

Edge: Rolex

44.6mm (47.9 x 44.6 x 12.3mm) vs 36mm — 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 Day-Date 18238 (18k yellow gold, blue diamond dial) at 36mm. 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 Day-Date 18238 (18k yellow gold, blue diamond dial) at $25,000+. On the specs that outlast any price: the MRW-230H uses Resin Glass with Approx. 3-year battery (SR626SW), against Sapphire Crystal, Cyclops and About 48 hours on the Day-Date 18238 (18k yellow gold, blue diamond dial). 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 Day-Date 18238 (18k yellow gold, blue diamond dial) 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

Day-Date 18238 (18k yellow gold, blue diamond dial)

Choose the Rolex Day-Date 18238 (18k yellow gold, blue diamond dial) if you value Rolex 3155, in-house automatic, chronometer technology, Swiss Made heritage, and 36mm proportions. At $25,000+, the Automatic, Rolex Calibre 3155 with About 48 hours power reserve makes it a compelling choice.

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The Bottom Line

The Casio MRW-230H and Rolex Day-Date 18238 (18k yellow gold, blue diamond dial) 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 Day-Date 18238 (18k yellow gold, blue diamond dial) 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 $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 Day-Date 18238 (18k yellow gold, blue diamond dial) 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 Day-Date 18238 (18k yellow gold, blue diamond dial) at 36mm with 100m (10 ATM) is similarly capable. The MRW-230H uses Resin Glass while the Day-Date 18238 (18k yellow gold, blue diamond dial) uses Sapphire Crystal, Cyclops.

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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.