Model guide · Reviewed
G-SHOCK GW-6900: Size, Battery Life, Water Resistance & Specs
Short answer
The G-SHOCK GW-6900 is a rounded three-window digital G-SHOCK with Tough Solar charging and Multi-Band 6 atomic timekeeping.
- Thickness
- 17.7 mm
- Weight
- 63 g (2.2 oz)
- Water resistance
- 200 m / 20 bar
- Power
- Solar, ~9 mo per charge
The GW-6900 brings solar power and radio-controlled time to the 6900 “Triple Graph” design that debuted in 1995. It sets itself from time signals broadcast by six stations, including the U.S. station near Fort Collins, Colorado, and recharges from any light. At 53.2 × 50 × 17.7 mm it is one of the chunkier classic G-SHOCKs, which is exactly why it suits bold moissanite bezels.
GW-6900 specifications
Casio's specifications for the stock GW-6900-1. Custom builds can differ; see the notes below.
| Reference | GW-6900-1 |
|---|---|
| Module | 3179, 3547 |
| Display | Digital |
| Shape | Rounded, three-window |
| Case size (L × W × H) | 53.2 × 50 × 17.7 mm (2.09 × 1.97 × 0.7 in) |
| Weight | 63 g (2.2 oz) |
| Case | Resin |
| Band | Resin |
| Water resistance | 200 m (660 ft, 20 bar) |
| Power | Tough Solar (rechargeable): about 9 months of normal use, about 26 months in darkness with power saving on a full charge |
| Tough Solar | Yes |
| Multi-Band 6 (atomic time) | Yes |
| Bluetooth | No |
| Light | Full auto backlight (EL on module 3179, LED on the GW-6900U) |
| Launched | 2009 (GW-6900); 2024 (GW-6900U, module 3547) |
| Casio U.S. list price | $155 |
The 2024 GW-6900U (module 3547) is rated about 10 months of normal use and 26 months in darkness with power saving on, and weighs 71 g (Casio U.S.).
Features
- Tough Solar charging
- Multi-Band 6 radio time sync (six stations incl. the U.S.)
- World time (31 time zones, 48 cities)
- 1/100-second stopwatch
- Countdown timer
- 5 daily alarms
- Battery level indicator
- Power saving
What is the G-SHOCK GW-6900?
The G-SHOCK GW-6900 is Casio's rounded three-window digital watch with Tough Solar power and Multi-Band 6 radio time sync. It is the solar, atomic version of the classic DW-6900 “Triple Graph” design from 1995.
How long does a GW-6900 last without light?
A fully charged GW-6900 runs about 9 months of normal use without light, or about 26 months in darkness with power saving on. The 2024 GW-6900U is rated about 10 months, and any regular light keeps either version charged.
Does the GW-6900 set itself in the United States?
Yes, the GW-6900's Multi-Band 6 receiver picks up the U.S. time signal from NIST station WWVB near Fort Collins, Colorado. Casio lists six stations in total: two in Japan, and one each in China, the United States, the United Kingdom and Germany.
How big is the GW-6900?
The GW-6900 measures 53.2 × 50 × 17.7 mm and weighs 63 g, according to G-Central's specification sheet. That is about 2.1 × 2 × 0.7 inches, noticeably chunkier than a GA-2100 or DW-5600.
Can you swim with a GW-6900?
The stock GW-6900 is rated 200 m (660 ft, 20 bar) water resistant, so swimming and showering are within its rating. It is not an ISO dive watch, and custom modifications can affect sealing, so confirm a custom piece with us first.
What module is in the GW-6900?
The GW-6900 uses Casio module 3179, and the 2024 GW-6900U uses module 3547. The number is printed on the case back and tells you which manual applies.
How much does a GW-6900 cost?
Casio's U.S. list price for the GW-6900-1 is $155, as recorded by G-Central, and it is often discounted. Bezelwright currently lists 8 custom GW-6900 builds from $130.
Is the GW-6900 right for you?
The GW-6900 suits
- Anyone who wants a maintenance-free digital G-SHOCK: no battery swaps, no time setting.
- Bigger wrists and bold styling — the round case wears with presence.
- Moissanite bezel builds that need a large, round canvas.
Look elsewhere if
- Small wrists or shirt cuffs — at 17.7 mm thick it is much chunkier than a GA-2100.
- Buyers who want analog hands.
Custom GW-6900 builds: what changes
- Our GW-6900 builds and GW-6900 moissanite bezels are made for the GW-6900 case; check the model on your case back before ordering a bezel.
- Custom modifications can affect water resistance; confirm a specific piece with us before swimming.
Bezelwright is an independent customizer and is not affiliated with Casio. Specs above describe Casio's stock model.
Custom GW-6900 builds (8, from $130)
Shop all GW-6900 builds
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Sources
Figures describe Casio's stock reference model. Independent references are used where Casio's own page could not be read directly, and cross-checked against Casio's published specs.
- G-Central: G-SHOCK GW-6900 specifications (independent reference, accessed October 25, 2026)
- Casio (U.S.): GW-6900U-1 specifications (official Casio, accessed October 25, 2026)
- Casio (U.S.): G-SHOCK 6900 series (official Casio, accessed October 25, 2026)
- Hahn's World of Surplus & Survival: Casio G-SHOCK GW-6900-1 listing (Casio spec sheet) (retailer listing of Casio's spec, accessed October 25, 2026)
- NIST: Help with WWVB radio controlled clocks (independent reference, accessed October 25, 2026)
- Casio G-SHOCK (UK): Are G-SHOCK watches waterproof or water resistant? (official Casio, accessed October 25, 2026)