Casio
G-Shock GA-2100
Ref. GA-2100-1A1 · “CasiOak”
- Case diameter
- 45.4 mm
- Manufacturer spec
- Lug-to-lug
- 48.5 mm
- Manufacturer spec
- Thickness
- 11.8 mm
- Manufacturer spec
- Lug width
- —
- Not published
Retail price $110 (US, Apr 2026)
Ideal fit
How the G-Shock GA-2100 wears
Its lugs add only 3.1 mm to the 45.4 mm case, against 7.1 mm typical across the almanac, so it wears smaller than its diameter suggests.
On our fit model it sits best on wrists from 6.75" to 8" (17.1–20.3 cm); below 6.75" the lugs start to reach the edge of the wrist.
At 11.8 mm thick it is slimmer than 70% of the 10 other digital watches we've measured, so it slides under a cuff more easily than most.
Will the G-Shock GA-2100 fit your wrist?
With a 48.5 mm lug-to-lug, here is how it wears across common wrist sizes. We estimate the flat top of each wrist from its circumference; measure yours for a closer answer in the fit finder.
| Wrist | Flat width (est.) | Fit |
|---|---|---|
| 6" | 47.2 mm | Lugs overhang |
| 6.5" | 51.2 mm | Snug, lugs near the edge |
| 7" | 55.1 mm | Ideal fit |
| 7.5" | 59.1 mm | Ideal fit |
| 8" | 63 mm | Ideal fit |
Specifications
- Reference
- GA-2100-1A1
- Collection
- G-Shock
- Status
- In production
- Introduced
- 2019
- Case material
- carbon / resin (Carbon Core Guard)
- Crystal
- mineral
- Water resistance
- 200 m
- Bezel
- fixed
- Dial
- black
- Strap / bracelet
- resin strap
- Weight
- 51 g
- Style
- Digital, Sport, Everyday
Movement
- Caliber
- Casio 5611
- Type
- quartz
- Accuracy
- +/-15 s/month
More G-Shock references
- CasioG-Shock DW-5600EDW-5600E-1V
- Case
- 42.8 mm
- Lug-to-lug
- 48.9 mm
- Thick
- 13.4 mm
- CasioG-Shock DW-6900DW-6900-1V
- Case
- 50 mm
- Lug-to-lug
- 53.2 mm
- Thick
- 18.7 mm
- CasioG-Shock GA-B2100GA-B2100-1A
- Case
- 45.4 mm
- Lug-to-lug
- 48.5 mm
- Thick
- 11.9 mm
- CasioG-Shock GW-5000UGW-5000U-1
- Case
- 42.8 mm
- Lug-to-lug
- 48.9 mm
- Thick
- 13.5 mm
- CasioG-Shock GW-M5610UGW-M5610U-1
- Case
- 43.2 mm
- Lug-to-lug
- 46.7 mm
- Thick
- 12.7 mm
Watches that wear the same size
Other watches within 1.5 mm of its lug-to-lug.
- CasioCasio Duro MDV-106MDV-106-1AV · “Duro”
- Case
- 44.2 mm
- Lug-to-lug
- 48.5 mm
- Thick
- 12.1 mm
- Grand SeikoElegance Spring DriveSBGA407 · “Skyflake”
- Case
- 40.2 mm
- Lug-to-lug
- 48.5 mm
- Thick
- 12.8 mm
- LonginesMaster Collection 41mm (2026)L2.950.4.73.6
- Case
- 41 mm
- Lug-to-lug
- 48.7 mm
- Thick
- 9.5 mm
- CertinaDS Super PH500MC037.407.18.050.00
- Case
- 43 mm
- Lug-to-lug
- 48.2 mm
- Thick
- 14.9 mm
- TudorNorthflag GMTM9140G1A0U
- Case
- 40 mm
- Lug-to-lug
- 48.8 mm
- Thick
- 12.7 mm
- Nomos GlashütteClub Campus 38735
- Case
- 38.5 mm
- Lug-to-lug
- 48.9 mm
- Thick
- 8.5 mm