Grand Seiko SBGX365
Ref. SBGX365 · In production
- Case32.3 mm
- Thick9 mm
- Lug-to-lug39 mm
- Water res.100 m
- MovementQuartz
- CrystalSapphire
Overview
The Grand Seiko SBGX365 is a sports watch from the Heritage collection, part of the Annual Accuracy Quartz family. It has a 32.3 mm stainless steel case, 9 mm thick, 39 mm from lug to lug. Inside is a quartz movement (calibre 9F51). You also get 100 m water resistance, a sapphire crystal and a bracelet.
Who it suits
- Wrists of roughly 13.1–14.6 cm (5.2–5.7 in), by our Watch Finder sizing guide
- Everyday wear including swimming
- Shirt cuffs and smarter dress codes
- Grab-and-go wear without winding or setting
Strengths
- Sapphire crystal resists scratches
- Rated accuracy: ±10 seconds per year
- Slim at 9 mm
- Compact 39 mm lug-to-lug suits smaller wrists
Written by Watch.co from the published specs below. These are not owner reviews.
Full specifications
Case
| Case diameter | 32.3 mm | grand-seiko.com · 23 Oct 2026 |
|---|---|---|
| Thickness | 9 mm | grand-seiko.com · 23 Oct 2026 |
| Lug-to-lug | 39 mm | grand-seiko.com · 23 Oct 2026 |
| Case material | Stainless steel | grand-seiko.com · 23 Oct 2026 |
| Crystal | Sapphire | grand-seiko.com · 23 Oct 2026 |
| Anti-reflective coating | Anti-reflective coating on inner surface | grand-seiko.com · 23 Oct 2026 |
| Caseback | Screw | grand-seiko.com · 23 Oct 2026 |
| Water resistance | 100 m | grand-seiko.com · 23 Oct 2026 |
| Magnetic resistance | 4,800 A/m | grand-seiko.com · 23 Oct 2026 |
Movement
| Movement type | Quartz | grand-seiko.com · 23 Oct 2026 |
|---|---|---|
| Calibre | 9F51 | grand-seiko.com · 23 Oct 2026 |
| Made in-house | Yes | grand-seiko.com · 23 Oct 2026 |
| Rated accuracy | ±10 seconds per year | grand-seiko.com · 23 Oct 2026 |
Strap / Bracelet
| Bracelet / strap | Bracelet | grand-seiko.com · 23 Oct 2026 |
|---|---|---|
| Lug width | 15 mm | grand-seiko.com · 23 Oct 2026 |
Other
| US list price (MSRP) | $3,600 | grand-seiko.com · 23 Oct 2026 |
|---|---|---|
| Production status | In production | grand-seiko.com · 23 Oct 2026 |
| Style (our classification) | Sports | our classification |
Specs are summarised in our own words from the brand's product page. Each row links its source and the date we checked it. Fields we haven't verified are left out rather than guessed.
Variants with the same specs
Same case, movement and bracelet or strap; typically a different dial or finish.
More in Annual Accuracy Quartz
Similar alternatives
Picked with Watch Finder's style tags and sizing.
Questions about the Grand Seiko SBGX365
How big is the Grand Seiko SBGX365?
The case is 32.3 mm wide, 9 mm thick and 39 mm from lug to lug.
What movement does the Grand Seiko SBGX365 use?
It uses the 9F51 calibre, a quartz movement.
Can I swim with the Grand Seiko SBGX365?
Yes. It is rated to 100 m.
How much is the Grand Seiko SBGX365?
The US list price was $3,600 on grand-seiko.com when we checked on 23 Oct 2026. Prices change, so check before you buy.
Will the Grand Seiko SBGX365 fit my wrist?
By our sizing guide it sits best on wrists of about 13.1–14.6 cm (5.2–5.7 in). Use the fit checker on this page to test your own wrist.
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