Citizen Watch Band Size by Model

Citizen is the brand where the retailer strap tables disagree with each other most, which is why this page exists. The same Chandler field watch is listed at 18mm, 20mm and 22mm by different fitment sites; the Promaster Diver gets mislisted at 21mm; and the Blue Angels chronograph hides a genuinely odd 23mm width. The table below lists the strap width between the lugs for the Citizen models people actually search for, every row checked against two independent sources, and the disagreements printed rather than averaged away.

The one-line answer: the Promaster Diver BN0150/BN0151 is 20mm, the Nighthawk is 22mm, the Blue Angels A-T is an odd 23mm, the Chandler BM8180 is 18mm (official spec; the 20mm and 22mm retailer listings are wrong), and the Tsuyosa is semi-integrated, so it takes curved-end straps only.

Citizen strap width by model

ModelCaseBand widthNotes
Promaster Diver BN0150 / BN0151 (Eco-Drive)42-43mm20mmSometimes mislisted 21mm; 20mm is verified
Promaster Diver BN0191 / BN019544mm22mmLarger Promaster divers step up to 22mm
Promaster Tough (BN0200 style)42-44mm22mmPer retailer fitment tables
Promaster Mechanical Diver NB602141mm20mmThe 62MAS-inspired mechanical diver
Nighthawk BJ7000 family (all variants)42mm22mmEvery BJ7000 through BJ7050 variant is 22mm
Blue Angels A-T / Skyhawk AT802043mm23mmThe odd size; do not squeeze a 22 or 24
Chandler BM818037mm18mmOfficial spec; 20/22mm retailer listings flagged below
Garrison AW0050 (43mm Eco-Drive field)43mm22mmDo not confuse with the 37mm Chandler
Eco-Drive Corso BM711040mm20mmDress line standard width
Tsuyosa NJ0150 / NJ015240mmintegratedSemi-integrated lugs; curved-end straps only
Eco-Drive Calendrier BU005440mm21mmAnother odd Citizen width
Promaster Sky CA4420 / Skyhawk variants44-45mm22mmPilot line runs 22mm

The Chandler disagreement, settled

The Chandler BM8180 is the row where Citizen strap tables fail. Watch Straps Australia lists it at 22mm, Lug and Leather's chart says 20mm, and CNS Watch Bands' reference table says 20mm for the BM7340 Chandler. Citizen's own US product page for the BM8180-03E says 18mm, and Millenary Watches' measured review and the Time Square Clock Shop dealer listing agree: 18mm lug width on a 37mm case. The retailer tables appear to be blending the Chandler with the larger 43mm Garrison, which really is 22mm. Buy 18mm for the BM8180, and treat any chart that does not distinguish Chandler from Garrison with suspicion.

The odd-size habit: 21mm and 23mm Citizens

Citizen is the one mainstream brand that routinely lands on odd lug widths, and it is worth understanding the pattern before shopping. The Blue Angels A-T (AT8020) is 23mm, confirmed by Citizen Europe's own spec sheet, aBlogtoWatch's measured review, and two independent strap retailers. The Calendrier line runs 21 to 23mm depending on reference. The practical consequence: aftermarket selection at 21 and 23mm is a fraction of what 20 and 22mm enjoy, and the temptation is to squeeze a neighboring even size onto the lugs, which leaves gaps and stresses the spring bars. An exact-size strap, even if the choice is narrower, is the correct buy.

Integrated and semi-integrated Citizens

The Tsuyosa NJ0150 looks like a normal 40mm watch with a 20mm-ish bracelet, but its lugs are semi-integrated: the bracelet's 9mm center links slot into cut-outs in the case, so a standard straight-end strap will not seat. Strap changes on a Tsuyosa mean curved-end aftermarket straps made for the model. The same logic applies to the Nighthawk's fitted bracelet ends and to Citizen's dress Stilettos. If the strap you are replacing has curved or shaped ends rather than a straight cut, assume the replacement must match that shape as well as the width. Measuring what you actually have is covered in the measuring guide.

Spring bar notes for Citizen owners

Citizen's standard-lug watches use ordinary spring bars, so the sizing and tooling on the spring bar sizes page applies directly: bar length equals lug width, and 1.5mm is the typical diameter for leather-and-rubber straps, 1.8mm for heavier bracelets. The "watch band pin size" question, which pin diameter a Citizen takes, is answered there rather than repeated here. For the tool itself, see the spring bar tool guide.

Related guides

For the sibling brands: the Seiko band size chart (watch for Seiko's fat 2.5mm diver bars) and the Casio strap size chart (G-Shocks take no standard strap). The brand-agnostic view of the same numbers is the lug width chart. Once you know the width: watch band materials compared, strap length by wrist, and how to adjust a watch band if the fit is close but not right. Case dimensions for the Promaster Diver are in the watch database, and whether a 43mm Nighthawk suits your wrist at all is the case size by wrist question. Also here: the Timex band size chart and the watch strap taper chart.

Sources