Side-by-side comparison of specifications and features
Compare visual case presence and physical footprint on one shared wrist. Measure your top-down wrist width for a stronger result; lug-to-lug is used when the catalog has it.
Medium (6.7″)
Estimated top width: 56.7 mm
Preliminary range: 54.7–61.8 mm.
Watch A
Visual presence
BoldCase covers 71% of your modeled wrist width.
Physical footprint
Clear spaceEstimated clearance: 5.3 mm per side.
Watch B
Visual presence
BoldCase covers 76% of your modeled wrist width.
Physical footprint
Clear spaceEstimated clearance: 5.2 mm per side.
Proportional guide only: visual presence and physical footprint do not predict comfort. Weight, thickness, caseback shape, rigid lugs, strap stiffness, wrist-bone prominence, wearing tension, bezel design, and case curvature change how a watch actually wears. Non-round silhouettes use a verified family shape and catalog dimensions where available; missing case height or width is estimated from a conservative family aspect ratio.
Start with the specifications that meaningfully differ. Expand the complete table for reference details and missing-data context.
| Specification | Casio G-Shock | Casio G-Shock |
|---|---|---|
| Pricing | ||
| MSRPG-Shock is $50 less at MSRP | $200 | $150 |
| New PriceG-Shock is $9 less based on the current snapshot | $129 | $120 |
| Used Price (Low)G-Shock is $54.6 less at the low end | $125 | $70 |
| Used Price (High) | $260 | $206 |
| 30-Day Trend | ↑ +26.4% | ↓ -9.3% |
| Used Price Range | $125 - $260 | $70 - $206 |
| Dimensions | ||
| DiameterG-Shock is 2.5mm smaller | 40.4mm | 42.9mm |
| ThicknessG-Shock is 0.2mm thinner | 11mm | 11.2mm |
| WeightG-Shock is 14g lighter | 55g | 41g |
| Lug to Lug | 46mm | 46.2mm |
| Case | ||
| Case Material | Stainless Steel | Resin |
Casio G-Shock GM-S2100 (small metal) and Casio G-Shock GMA-S2100 (small) can overlap on price or use case, but the buying decision usually comes down to wrist presence versus easier fit. They both touch the ana-digi and sports use case, so smaller spec differences can matter more than brand preference.
Bottom line
Fit is a real separator here — compare case width and lug-to-lug before deciding, especially if wrist comfort matters more than headline features. Choose Casio G-Shock GM-S2100 (small metal) if you want a smaller case footprint on the wrist; choose Casio G-Shock GMA-S2100 (small) if you prefer more dial presence and a larger case feel.
Choose Casio G-Shock GM-S2100 (small metal) when
Casio G-Shock GM-S2100 (small metal) is a better fit for smaller wrists, low-maintenance daily wear, ana-digi styling.
Choose Casio G-Shock GMA-S2100 (small) when
Casio G-Shock GMA-S2100 (small) is a better fit for buyers who want more wrist presence, low-maintenance daily wear, ana-digi styling.
Movement and upkeep
Casio G-Shock GM-S2100 (small metal): quartz movement
Casio G-Shock GMA-S2100 (small): quartz movement
Both use the same movement type, so maintenance differences are limited and fit or feature details should decide the purchase.
Size and wearability
Casio G-Shock GM-S2100 (small metal): 40.4mm · L2L 46mm · 55g
Casio G-Shock GMA-S2100 (small): 42.9mm · L2L 46.2mm · 41g
Fit is a real separator here — compare case width and lug-to-lug before deciding, especially if wrist comfort matters more than headline features.
Water resistance
Casio G-Shock GM-S2100 (small metal): 200m
Casio G-Shock GMA-S2100 (small): 200m
Water resistance is similar on paper, so focus on fit, features, and price instead.
Price and value
Casio G-Shock GM-S2100 (small metal): $129
Casio G-Shock GMA-S2100 (small): $120
These two often land in a similar price band — which usually means fit, features, and current deal quality matter more than the sticker price.
Style and use case
Casio G-Shock GM-S2100 (small metal): ana-digi
Casio G-Shock GMA-S2100 (small): ana-digi
Both lean into a similar ana-digi use case — the choice is more about fit, features, and price than category.
Crystal and materials
Casio G-Shock GM-S2100 (small metal): mineral crystal · steel
Casio G-Shock GMA-S2100 (small): mineral crystal · resin
Materials are broadly similar, so finish, fit, and price will matter more than the materials list alone.
Casio G-Shock GM-S2100 (small metal) and Casio G-Shock GMA-S2100 (small) get compared constantly because both are ana-digi/sports watches, they share the same quartz movement, they sit in the same price band — so the spec sheet alone will not tell you which to buy.
Casio G-Shock GM-S2100 (small metal) — Casio G-Shock GM-S2100 (small metal) uses a steel case, Casio G-Shock GMA-S2100 (small) a resin case — that changes both weight and how premium it feels.
Casio G-Shock GMA-S2100 (small) — Casio G-Shock GM-S2100 (small metal) is 55g and Casio G-Shock GMA-S2100 (small) is 41g — a 14g gap is noticeable over a full day.
Casio G-Shock GMA-S2100 (small) for most buyers — Casio G-Shock GM-S2100 (small metal) is 55g and Casio G-Shock GMA-S2100 (small) is 41g — a 14g gap is noticeable over a full day. Go with Casio G-Shock GM-S2100 (small metal) instead if you want the more substantial steel case rather than resin.
Casio G-Shock GMA-S2100 (small) usually offers the lower entry price — confirm current listings because marketplace pricing can move quickly.
These two often land in a similar price band — which usually means fit, features, and current deal quality matter more than the sticker price.
Check current deals on Amazon and eBay using the buttons below — listing prices, seller quality, and condition can change quickly.
Prices change often, so compare the latest listings and condition options before you buy.
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Casio G-Shock
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Casio G-Shock
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Casio G-Shock GM-S2100 (small metal) — it is 40.4mm wide versus 42.9mm. Thickness is 11mm vs 11.2mm, which also affects how it sits.
They are rated the same, so water resistance will not decide this. Choose on strap material and how much you mind scratching the case.
Casio G-Shock GMA-S2100 (small) is the value pick at roughly $9 less. Pay more only if a specific difference above matters to you — otherwise the cheaper one is the smarter buy. Confirm live listings, since marketplace pricing moves.
Casio G-Shock GM-S2100 (small metal) is 55g and Casio G-Shock GMA-S2100 (small) is 41g — a 14g gap is noticeable over a full day. That is the difference you will notice day to day; the rest of the specs are close enough not to matter.
Casio G-Shock GMA-S2100 (small) for most buyers — Casio G-Shock GM-S2100 (small metal) is 55g and Casio G-Shock GMA-S2100 (small) is 41g — a 14g gap is noticeable over a full day. Go with Casio G-Shock GM-S2100 (small metal) instead if you want the more substantial steel case rather than resin.
Evidence & Method
This page currently relies on normalized catalog fields and calculated differences. No external reviewer observation is used in its verdict.
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